internal/rosa/llvm: arch-specific patches

Broken aarch64 tests in LLVM seem unlikely to be fixed soon.

Signed-off-by: Ophestra <cat@gensokyo.uk>

.gitea/workflows/test.yml

@@ -89,23 +89,6 @@ jobs:
           path: result/*
           retention-days: 1
 
-  hpkg:
-    name: Hpkg
-    runs-on: nix
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Run NixOS test
-        run: nix build --out-link "result" --print-out-paths --print-build-logs .#checks.x86_64-linux.hpkg
-
-      - name: Upload test output
-        uses: actions/upload-artifact@v3
-        with:
-          name: "hpkg-vm-output"
-          path: result/*
-          retention-days: 1
-
   check:
     name: Flake checks
     needs:
@@ -114,7 +97,6 @@ jobs:
       - sandbox
       - sandbox-race
       - sharefs
-      - hpkg
     runs-on: nix
     steps:
       - name: Checkout

.github/workflows/README

@@ -1,5 +0,0 @@
-DO NOT ADD NEW ACTIONS HERE
-
-This port is solely for releasing to the github mirror and serves no purpose during development.
-All development happens at https://git.gensokyo.uk/security/hakurei. If you wish to contribute,
-request for an account on git.gensokyo.uk.

.github/workflows/release.yml

@@ -1,46 +0,0 @@
-name: Release
-
-on:
-  push:
-    tags:
-      - 'v*'
-
-jobs:
-  release:
-    name: Create release
-    runs-on: ubuntu-latest
-
-    permissions:
-      packages: write
-      contents: write
-
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Install Nix
-        uses: nixbuild/nix-quick-install-action@v32
-        with:
-          nix_conf: |
-            keep-env-derivations = true
-            keep-outputs = true
-
-      - name: Restore and cache Nix store
-        uses: nix-community/cache-nix-action@v6
-        with:
-          primary-key: build-${{ runner.os }}-${{ hashFiles('**/*.nix') }}
-          restore-prefixes-first-match: build-${{ runner.os }}-
-          gc-max-store-size-linux: 1G
-          purge: true
-          purge-prefixes: build-${{ runner.os }}-
-          purge-created: 60
-          purge-primary-key: never
-
-      - name: Build for release
-        run: nix build --print-out-paths --print-build-logs .#dist
-
-      - name: Release
-        uses: softprops/action-gh-release@v2
-        with:
-          files: |-
-            result/hakurei-**

.github/workflows/test.yml

@@ -1,48 +0,0 @@
-name: Test
-
-on:
-  - push
-
-jobs:
-  dist:
-    name: Create distribution
-    runs-on: ubuntu-latest
-    permissions:
-      actions: write
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Install Nix
-        uses: nixbuild/nix-quick-install-action@v32
-        with:
-          nix_conf: |
-            keep-env-derivations = true
-            keep-outputs = true
-
-      - name: Restore and cache Nix store
-        uses: nix-community/cache-nix-action@v6
-        with:
-          primary-key: build-${{ runner.os }}-${{ hashFiles('**/*.nix') }}
-          restore-prefixes-first-match: build-${{ runner.os }}-
-          gc-max-store-size-linux: 1G
-          purge: true
-          purge-prefixes: build-${{ runner.os }}-
-          purge-created: 60
-          purge-primary-key: never
-
-      - name: Build for test
-        id: build-test
-        run: >-
-          export HAKUREI_REV="$(git rev-parse --short HEAD)" &&
-          sed -i.old 's/version = /version = "0.0.0-'$HAKUREI_REV'"; # version = /' package.nix &&
-          nix build --print-out-paths --print-build-logs .#dist &&
-          mv package.nix.old package.nix &&
-          echo "rev=$HAKUREI_REV" >> $GITHUB_OUTPUT
-
-      - name: Upload test build
-        uses: actions/upload-artifact@v4
-        with:
-          name: "hakurei-${{ steps.build-test.outputs.rev }}"
-          path: result/*
-          retention-days: 1

.gitignore

@@ -28,6 +28,7 @@ go.work.sum
 # go generate
 /cmd/hakurei/LICENSE
 /internal/pkg/testdata/testtool
+/internal/rosa/hakurei_current.tar.gz
 
 # release
 /dist/hakurei-*

README.md

@@ -15,164 +15,51 @@
   <a href="https://hakurei.app"><img src="https://img.shields.io/website?url=https%3A%2F%2Fhakurei.app" alt="Website" /></a>
 </p>
 
-Hakurei is a tool for running sandboxed graphical applications as dedicated subordinate users on the Linux kernel.
-It implements the application container of [planterette (WIP)](https://git.gensokyo.uk/security/planterette),
-a self-contained Android-like package manager with modern security features.
+Hakurei is a tool for running sandboxed desktop applications as dedicated
+subordinate users on the Linux kernel. It implements the application container
+of [planterette (WIP)](https://git.gensokyo.uk/security/planterette), a
+self-contained Android-like package manager with modern security features.
 
-## NixOS Module usage
+Interaction with hakurei happens entirely through structures described by
+package [hst](https://pkg.go.dev/hakurei.app/hst). No native API is available
+due to internal details of uid isolation.
 
-The NixOS module currently requires home-manager to configure subordinate users. Full module documentation can be found [here](options.md).
+## Notable Packages
 
-To use the module, import it into your configuration with
+Package [container](https://pkg.go.dev/hakurei.app/container) is general purpose
+container tooling. It is used by the hakurei shim process running as the target
+subordinate user to set up the application container. It has a single dependency,
+[libseccomp](https://github.com/seccomp/libseccomp), to create BPF programs
+for the [system call filter](https://www.kernel.org/doc/html/latest/userspace-api/seccomp_filter.html).
 
-```nix
-{
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
+Package [internal/pkg](https://pkg.go.dev/hakurei.app/internal/pkg) provides
+infrastructure for hermetic builds. This replaces the legacy nix-based testing
+framework and serves as the build system of Rosa OS, currently developed under
+package [internal/rosa](https://pkg.go.dev/hakurei.app/internal/rosa).
 
-    hakurei = {
-      url = "git+https://git.gensokyo.uk/security/hakurei";
+## Dependencies
 
-      # Optional but recommended to limit the size of your system closure.
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
-  };
+`container` depends on:
 
-  outputs = { self, nixpkgs, hakurei, ... }:
-  {
-    nixosConfigurations.hakurei = nixpkgs.lib.nixosSystem {
-      system = "x86_64-linux";
-      modules = [
-        hakurei.nixosModules.hakurei
-      ];
-    };
-  };
-}
-```
+- [libseccomp](https://github.com/seccomp/libseccomp) to generate BPF programs.
 
-This adds the `environment.hakurei` option:
+`cmd/hakurei` depends on:
 
-```nix
-{ pkgs, ... }:
+- [acl](https://savannah.nongnu.org/projects/acl/) to export sockets to
+  subordinate users.
+- [wayland](https://gitlab.freedesktop.org/wayland/wayland) to set up
+  [security-context-v1](https://wayland.app/protocols/security-context-v1).
+- [xcb](https://xcb.freedesktop.org/) to grant and revoke subordinate users
+  access to the X server.
 
-{
-  environment.hakurei = {
-    enable = true;
-    stateDir = "/var/lib/hakurei";
-    users = {
-      alice = 0;
-      nixos = 10;
-    };
+`cmd/sharefs` depends on:
 
-    commonPaths = [
-      {
-        src = "/sdcard";
-        write = true;
-      }
-    ];
+- [fuse](https://github.com/libfuse/libfuse) to implement the filesystem.
 
-    extraHomeConfig = {
-      home.stateVersion = "23.05";
-    };
+New dependencies will generally not be added. Patches adding new dependencies
+are very likely to be rejected.
 
-    apps = {
-      "org.chromium.Chromium" = {
-        name = "chromium";
-        identity = 1;
-        packages = [ pkgs.chromium ];
-        userns = true;
-        mapRealUid = true;
-        dbus = {
-          system = {
-            filter = true;
-            talk = [
-              "org.bluez"
-              "org.freedesktop.Avahi"
-              "org.freedesktop.UPower"
-            ];
-          };
-          session =
-            f:
-            f {
-              talk = [
-                "org.freedesktop.FileManager1"
-                "org.freedesktop.Notifications"
-                "org.freedesktop.ScreenSaver"
-                "org.freedesktop.secrets"
-                "org.kde.kwalletd5"
-                "org.kde.kwalletd6"
-              ];
-              own = [
-                "org.chromium.Chromium.*"
-                "org.mpris.MediaPlayer2.org.chromium.Chromium.*"
-                "org.mpris.MediaPlayer2.chromium.*"
-              ];
-              call = { };
-              broadcast = { };
-            };
-        };
-      };
+## NixOS Module (deprecated)
 
-      "org.claws_mail.Claws-Mail" = {
-        name = "claws-mail";
-        identity = 2;
-        packages = [ pkgs.claws-mail ];
-        gpu = false;
-        capability.pulse = false;
-      };
-
-      "org.weechat" = {
-        name = "weechat";
-        identity = 3;
-        shareUid = true;
-        packages = [ pkgs.weechat ];
-        capability = {
-          wayland = false;
-          x11 = false;
-          dbus = true;
-          pulse = false;
-        };
-      };
-
-      "dev.vencord.Vesktop" = {
-        name = "discord";
-        identity = 3;
-        shareUid = true;
-        packages = [ pkgs.vesktop ];
-        share = pkgs.vesktop;
-        command = "vesktop --ozone-platform-hint=wayland";
-        userns = true;
-        mapRealUid = true;
-        capability.x11 = true;
-        dbus = {
-          session =
-            f:
-            f {
-              talk = [ "org.kde.StatusNotifierWatcher" ];
-              own = [ ];
-              call = { };
-              broadcast = { };
-            };
-          system.filter = true;
-        };
-      };
-
-      "io.looking-glass" = {
-        name = "looking-glass-client";
-        identity = 4;
-        useCommonPaths = false;
-        groups = [ "plugdev" ];
-        extraPaths = [
-          {
-            src = "/dev/shm/looking-glass";
-            write = true;
-          }
-        ];
-        extraConfig = {
-          programs.looking-glass-client.enable = true;
-        };
-      };
-    };
-  };
-}
-```
+The NixOS module is in maintenance mode and will be removed once planterette is
+feature-complete. Full module documentation can be found [here](options.md).

cmd/earlyinit/main.go

@@ -0,0 +1,127 @@
+package main
+
+import (
+	"log"
+	"os"
+	"runtime"
+	"strings"
+	. "syscall"
+)
+
+func main() {
+	runtime.LockOSThread()
+	log.SetFlags(0)
+	log.SetPrefix("earlyinit: ")
+
+	var (
+		option map[string]string
+		flags  []string
+	)
+	if len(os.Args) > 1 {
+		option = make(map[string]string)
+		for _, s := range os.Args[1:] {
+			key, value, ok := strings.Cut(s, "=")
+			if !ok {
+				flags = append(flags, s)
+				continue
+			}
+			option[key] = value
+		}
+	}
+
+	if err := Mount(
+		"devtmpfs",
+		"/dev/",
+		"devtmpfs",
+		MS_NOSUID|MS_NOEXEC,
+		"",
+	); err != nil {
+		log.Fatalf("cannot mount devtmpfs: %v", err)
+	}
+
+	// The kernel might be unable to set up the console. When that happens,
+	// printk is called with "Warning: unable to open an initial console."
+	// and the init runs with no files. The checkfds runtime function
+	// populates 0-2 by opening /dev/null for them.
+	//
+	// This check replaces 1 and 2 with /dev/kmsg to improve the chance
+	// of output being visible to the user.
+	if fi, err := os.Stdout.Stat(); err == nil {
+		if stat, ok := fi.Sys().(*Stat_t); ok {
+			if stat.Rdev == 0x103 {
+				var fd int
+				if fd, err = Open(
+					"/dev/kmsg",
+					O_WRONLY|O_CLOEXEC,
+					0,
+				); err != nil {
+					log.Fatalf("cannot open kmsg: %v", err)
+				}
+
+				if err = Dup3(fd, Stdout, 0); err != nil {
+					log.Fatalf("cannot open stdout: %v", err)
+				}
+				if err = Dup3(fd, Stderr, 0); err != nil {
+					log.Fatalf("cannot open stderr: %v", err)
+				}
+
+				if err = Close(fd); err != nil {
+					log.Printf("cannot close kmsg: %v", err)
+				}
+			}
+		}
+	}
+
+	// staying in rootfs, these are no longer used
+	must(os.Remove("/root"))
+	must(os.Remove("/init"))
+
+	must(os.Mkdir("/proc", 0))
+	mustSyscall("mount proc", Mount(
+		"proc",
+		"/proc",
+		"proc",
+		MS_NOSUID|MS_NOEXEC|MS_NODEV,
+		"hidepid=1",
+	))
+
+	must(os.Mkdir("/sys", 0))
+	mustSyscall("mount sysfs", Mount(
+		"sysfs",
+		"/sys",
+		"sysfs",
+		0,
+		"",
+	))
+
+	// after top level has been set up
+	mustSyscall("remount root", Mount(
+		"",
+		"/",
+		"",
+		MS_REMOUNT|MS_BIND|
+			MS_RDONLY|MS_NODEV|MS_NOSUID|MS_NOEXEC,
+		"",
+	))
+
+	must(os.WriteFile(
+		"/sys/module/firmware_class/parameters/path",
+		[]byte("/system/lib/firmware"),
+		0,
+	))
+
+}
+
+// mustSyscall calls [log.Fatalln] if err is non-nil.
+func mustSyscall(action string, err error) {
+	if err != nil {
+		log.Fatalln("cannot "+action+":", err)
+	}
+}
+
+// must calls [log.Fatal] with err if it is non-nil.
+func must(err error) {
+	if err != nil {
+		log.Fatal(err)
+	}
+}

cmd/hakurei/command.go

@@ -16,6 +16,7 @@ import (
 	"hakurei.app/command"
 	"hakurei.app/container/check"
 	"hakurei.app/container/fhs"
+	"hakurei.app/container/std"
 	"hakurei.app/hst"
 	"hakurei.app/internal/dbus"
 	"hakurei.app/internal/env"
@@ -89,6 +90,9 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 			flagHomeDir  string
 			flagUserName string
 
+			flagSchedPolicy   string
+			flagSchedPriority int
+
 			flagPrivateRuntime, flagPrivateTmpdir bool
 
 			flagWayland, flagX11, flagDBus, flagPipeWire, flagPulse bool
@@ -131,7 +135,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 					log.Fatal(optionalErrorUnwrap(err))
 					return err
 				} else if progPath, err = check.NewAbs(p); err != nil {
-					log.Fatal(err.Error())
+					log.Fatal(err)
 					return err
 				}
 			}
@@ -150,7 +154,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				et |= hst.EPipeWire
 			}
 
-			config := &hst.Config{
+			config := hst.Config{
 				ID:          flagID,
 				Identity:    flagIdentity,
 				Groups:      flagGroups,
@@ -177,6 +181,13 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				},
 			}
 
+			if err := config.SchedPolicy.UnmarshalText(
+				[]byte(flagSchedPolicy),
+			); err != nil {
+				log.Fatal(err)
+			}
+			config.SchedPriority = std.Int(flagSchedPriority)
+
 			// bind GPU stuff
 			if et&(hst.EX11|hst.EWayland) != 0 {
 				config.Container.Filesystem = append(config.Container.Filesystem, hst.FilesystemConfigJSON{FilesystemConfig: &hst.FSBind{
@@ -214,7 +225,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 					homeDir = passwd.HomeDir
 				}
 				if a, err := check.NewAbs(homeDir); err != nil {
-					log.Fatal(err.Error())
+					log.Fatal(err)
 					return err
 				} else {
 					config.Container.Home = a
@@ -234,11 +245,11 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 					config.SessionBus = dbus.NewConfig(flagID, true, flagDBusMpris)
 				} else {
 					if f, err := os.Open(flagDBusConfigSession); err != nil {
-						log.Fatal(err.Error())
+						log.Fatal(err)
 					} else {
 						decodeJSON(log.Fatal, "load session bus proxy config", f, &config.SessionBus)
 						if err = f.Close(); err != nil {
-							log.Fatal(err.Error())
+							log.Fatal(err)
 						}
 					}
 				}
@@ -246,11 +257,11 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				// system bus proxy is optional
 				if flagDBusConfigSystem != "nil" {
 					if f, err := os.Open(flagDBusConfigSystem); err != nil {
-						log.Fatal(err.Error())
+						log.Fatal(err)
 					} else {
 						decodeJSON(log.Fatal, "load system bus proxy config", f, &config.SystemBus)
 						if err = f.Close(); err != nil {
-							log.Fatal(err.Error())
+							log.Fatal(err)
 						}
 					}
 				}
@@ -266,7 +277,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				}
 			}
 
-			outcome.Main(ctx, msg, config, -1)
+			outcome.Main(ctx, msg, &config, -1)
 			panic("unreachable")
 		}).
 			Flag(&flagDBusConfigSession, "dbus-config", command.StringFlag("builtin"),
@@ -287,6 +298,10 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				"Container home directory").
 			Flag(&flagUserName, "u", command.StringFlag("chronos"),
 				"Passwd user name within sandbox").
+			Flag(&flagSchedPolicy, "policy", command.StringFlag(""),
+				"Scheduling policy to set for the container").
+			Flag(&flagSchedPriority, "priority", command.IntFlag(0),
+				"Scheduling priority to set for the container").
 			Flag(&flagPrivateRuntime, "private-runtime", command.BoolFlag(false),
 				"Do not share XDG_RUNTIME_DIR between containers under the same identity").
 			Flag(&flagPrivateTmpdir, "private-tmpdir", command.BoolFlag(false),

cmd/hakurei/command_test.go

@@ -36,7 +36,7 @@ Commands:
 		},
 		{
 			"run", []string{"run", "-h"}, `
-Usage:	hakurei run [-h | --help] [--dbus-config <value>] [--dbus-system <value>] [--mpris] [--dbus-log] [--id <value>] [-a <int>] [-g <value>] [-d <value>] [-u <value>] [--private-runtime] [--private-tmpdir] [--wayland] [-X] [--dbus] [--pipewire] [--pulse] COMMAND [OPTIONS]
+Usage:	hakurei run [-h | --help] [--dbus-config <value>] [--dbus-system <value>] [--mpris] [--dbus-log] [--id <value>] [-a <int>] [-g <value>] [-d <value>] [-u <value>] [--policy <value>] [--priority <int>] [--private-runtime] [--private-tmpdir] [--wayland] [-X] [--dbus] [--pipewire] [--pulse] COMMAND [OPTIONS]
 
 Flags:
   -X	Enable direct connection to X11
@@ -60,6 +60,10 @@ Flags:
     	Allow owning MPRIS D-Bus path, has no effect if custom config is available
   -pipewire
     	Enable connection to PipeWire via SecurityContext
+  -policy string
+    	Scheduling policy to set for the container
+  -priority int
+    	Scheduling priority to set for the container
   -private-runtime
     	Do not share XDG_RUNTIME_DIR between containers under the same identity
   -private-tmpdir

cmd/hpkg/README

@@ -1,7 +0,0 @@
-This program is a proof of concept and is now deprecated. It is only kept
-around for API demonstration purposes and to make the most out of the test
-suite.
-
-This program is replaced by planterette, which can be found at
-https://git.gensokyo.uk/security/planterette. Development effort should be
-focused there instead.

cmd/hpkg/app.go

@@ -1,173 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"log"
-	"os"
-
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
-	"hakurei.app/hst"
-)
-
-type appInfo struct {
-	Name    string `json:"name"`
-	Version string `json:"version"`
-
-	// passed through to [hst.Config]
-	ID string `json:"id"`
-	// passed through to [hst.Config]
-	Identity int `json:"identity"`
-	// passed through to [hst.Config]
-	Groups []string `json:"groups,omitempty"`
-	// passed through to [hst.Config]
-	Devel bool `json:"devel,omitempty"`
-	// passed through to [hst.Config]
-	Userns bool `json:"userns,omitempty"`
-	// passed through to [hst.Config]
-	HostNet bool `json:"net,omitempty"`
-	// passed through to [hst.Config]
-	HostAbstract bool `json:"abstract,omitempty"`
-	// passed through to [hst.Config]
-	Device bool `json:"dev,omitempty"`
-	// passed through to [hst.Config]
-	Tty bool `json:"tty,omitempty"`
-	// passed through to [hst.Config]
-	MapRealUID bool `json:"map_real_uid,omitempty"`
-	// passed through to [hst.Config]
-	DirectWayland bool `json:"direct_wayland,omitempty"`
-	// passed through to [hst.Config]
-	SystemBus *hst.BusConfig `json:"system_bus,omitempty"`
-	// passed through to [hst.Config]
-	SessionBus *hst.BusConfig `json:"session_bus,omitempty"`
-	// passed through to [hst.Config]
-	Enablements *hst.Enablements `json:"enablements,omitempty"`
-
-	// passed through to [hst.Config]
-	Multiarch bool `json:"multiarch,omitempty"`
-	// passed through to [hst.Config]
-	Bluetooth bool `json:"bluetooth,omitempty"`
-
-	// allow gpu access within sandbox
-	GPU bool `json:"gpu"`
-	// store path to nixGL mesa wrappers
-	Mesa string `json:"mesa,omitempty"`
-	// store path to nixGL source
-	NixGL string `json:"nix_gl,omitempty"`
-	// store path to activate-and-exec script
-	Launcher *check.Absolute `json:"launcher"`
-	// store path to /run/current-system
-	CurrentSystem *check.Absolute `json:"current_system"`
-	// store path to home-manager activation package
-	ActivationPackage string `json:"activation_package"`
-}
-
-func (app *appInfo) toHst(pathSet *appPathSet, pathname *check.Absolute, argv []string, flagDropShell bool) *hst.Config {
-	config := &hst.Config{
-		ID: app.ID,
-
-		Enablements: app.Enablements,
-
-		SystemBus:     app.SystemBus,
-		SessionBus:    app.SessionBus,
-		DirectWayland: app.DirectWayland,
-
-		Identity: app.Identity,
-		Groups:   app.Groups,
-
-		Container: &hst.ContainerConfig{
-			Hostname: formatHostname(app.Name),
-			Filesystem: []hst.FilesystemConfigJSON{
-				{FilesystemConfig: &hst.FSBind{Target: fhs.AbsEtc, Source: pathSet.cacheDir.Append("etc"), Special: true}},
-				{FilesystemConfig: &hst.FSBind{Source: pathSet.nixPath.Append("store"), Target: pathNixStore}},
-				{FilesystemConfig: &hst.FSLink{Target: pathCurrentSystem, Linkname: app.CurrentSystem.String()}},
-				{FilesystemConfig: &hst.FSLink{Target: pathBin, Linkname: pathSwBin.String()}},
-				{FilesystemConfig: &hst.FSLink{Target: fhs.AbsUsrBin, Linkname: pathSwBin.String()}},
-				{FilesystemConfig: &hst.FSBind{Source: pathSet.metaPath, Target: hst.AbsPrivateTmp.Append("app")}},
-				{FilesystemConfig: &hst.FSBind{Source: fhs.AbsEtc.Append("resolv.conf"), Optional: true}},
-				{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("block"), Optional: true}},
-				{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("bus"), Optional: true}},
-				{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("class"), Optional: true}},
-				{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("dev"), Optional: true}},
-				{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("devices"), Optional: true}},
-				{FilesystemConfig: &hst.FSBind{Target: pathDataData.Append(app.ID), Source: pathSet.homeDir, Write: true, Ensure: true}},
-			},
-
-			Username: "hakurei",
-			Shell:    pathShell,
-			Home:     pathDataData.Append(app.ID),
-
-			Path: pathname,
-			Args: argv,
-		},
-		ExtraPerms: []hst.ExtraPermConfig{
-			{Path: dataHome, Execute: true},
-			{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
-		},
-	}
-
-	if app.Devel {
-		config.Container.Flags |= hst.FDevel
-	}
-	if app.Userns {
-		config.Container.Flags |= hst.FUserns
-	}
-	if app.HostNet {
-		config.Container.Flags |= hst.FHostNet
-	}
-	if app.HostAbstract {
-		config.Container.Flags |= hst.FHostAbstract
-	}
-	if app.Device {
-		config.Container.Flags |= hst.FDevice
-	}
-	if app.Tty || flagDropShell {
-		config.Container.Flags |= hst.FTty
-	}
-	if app.MapRealUID {
-		config.Container.Flags |= hst.FMapRealUID
-	}
-	if app.Multiarch {
-		config.Container.Flags |= hst.FMultiarch
-	}
-	config.Container.Flags |= hst.FShareRuntime | hst.FShareTmpdir
-	return config
-}
-
-func loadAppInfo(name string, beforeFail func()) *appInfo {
-	bundle := new(appInfo)
-	if f, err := os.Open(name); err != nil {
-		beforeFail()
-		log.Fatalf("cannot open bundle: %v", err)
-	} else if err = json.NewDecoder(f).Decode(&bundle); err != nil {
-		beforeFail()
-		log.Fatalf("cannot parse bundle metadata: %v", err)
-	} else if err = f.Close(); err != nil {
-		log.Printf("cannot close bundle metadata: %v", err)
-		// not fatal
-	}
-
-	if bundle.ID == "" {
-		beforeFail()
-		log.Fatal("application identifier must not be empty")
-	}
-	if bundle.Launcher == nil {
-		beforeFail()
-		log.Fatal("launcher must not be empty")
-	}
-	if bundle.CurrentSystem == nil {
-		beforeFail()
-		log.Fatal("current-system must not be empty")
-	}
-
-	return bundle
-}
-
-func formatHostname(name string) string {
-	if h, err := os.Hostname(); err != nil {
-		log.Printf("cannot get hostname: %v", err)
-		return "hakurei-" + name
-	} else {
-		return h + "-" + name
-	}
-}

cmd/hpkg/build.nix

@@ -1,256 +0,0 @@
-{
-  nixpkgsFor,
-  system,
-  nixpkgs,
-  home-manager,
-}:
-
-{
-  lib,
-  stdenv,
-  closureInfo,
-  writeScript,
-  runtimeShell,
-  writeText,
-  symlinkJoin,
-  vmTools,
-  runCommand,
-  fetchFromGitHub,
-
-  zstd,
-  nix,
-  sqlite,
-
-  name ? throw "name is required",
-  version ? throw "version is required",
-  pname ? "${name}-${version}",
-  modules ? [ ],
-  nixosModules ? [ ],
-  script ? ''
-    exec "$SHELL" "$@"
-  '',
-
-  id ? name,
-  identity ? throw "identity is required",
-  groups ? [ ],
-  userns ? false,
-  net ? true,
-  dev ? false,
-  no_new_session ? false,
-  map_real_uid ? false,
-  direct_wayland ? false,
-  system_bus ? null,
-  session_bus ? null,
-
-  allow_wayland ? true,
-  allow_x11 ? false,
-  allow_dbus ? true,
-  allow_audio ? true,
-  gpu ? allow_wayland || allow_x11,
-}:
-
-let
-  inherit (lib) optionals;
-
-  homeManagerConfiguration = home-manager.lib.homeManagerConfiguration {
-    pkgs = nixpkgsFor.${system};
-    modules = modules ++ [
-      {
-        home = {
-          username = "hakurei";
-          homeDirectory = "/data/data/${id}";
-          stateVersion = "22.11";
-        };
-      }
-    ];
-  };
-
-  launcher = writeScript "hakurei-${pname}" ''
-    #!${runtimeShell} -el
-    ${script}
-  '';
-
-  extraNixOSConfig =
-    { pkgs, ... }:
-    {
-      environment = {
-        etc.nixpkgs.source = nixpkgs.outPath;
-        systemPackages = [ pkgs.nix ];
-      };
-
-      imports = nixosModules;
-    };
-  nixos = nixpkgs.lib.nixosSystem {
-    inherit system;
-    modules = [
-      extraNixOSConfig
-      { nix.settings.experimental-features = [ "flakes" ]; }
-      { nix.settings.experimental-features = [ "nix-command" ]; }
-      { boot.isContainer = true; }
-      { system.stateVersion = "22.11"; }
-    ];
-  };
-
-  etc = vmTools.runInLinuxVM (
-    runCommand "etc" { } ''
-      mkdir -p /etc
-      ${nixos.config.system.build.etcActivationCommands}
-
-      # remove unused files
-      rm -rf /etc/sudoers
-
-      mkdir -p $out
-      tar -C /etc -cf "$out/etc.tar" .
-    ''
-  );
-
-  extendSessionDefault = id: ext: {
-    filter = true;
-
-    talk = [ "org.freedesktop.Notifications" ] ++ ext.talk;
-    own =
-      (optionals (id != null) [
-        "${id}.*"
-        "org.mpris.MediaPlayer2.${id}.*"
-      ])
-      ++ ext.own;
-
-    inherit (ext) call broadcast;
-  };
-
-  nixGL = fetchFromGitHub {
-    owner = "nix-community";
-    repo = "nixGL";
-    rev = "310f8e49a149e4c9ea52f1adf70cdc768ec53f8a";
-    hash = "sha256-lnzZQYG0+EXl/6NkGpyIz+FEOc/DSEG57AP1VsdeNrM=";
-  };
-
-  mesaWrappers =
-    let
-      isIntelX86Platform = system == "x86_64-linux";
-      nixGLPackages = import (nixGL + "/default.nix") {
-        pkgs = nixpkgs.legacyPackages.${system};
-        enable32bits = isIntelX86Platform;
-        enableIntelX86Extensions = isIntelX86Platform;
-      };
-    in
-    symlinkJoin {
-      name = "nixGL-mesa";
-      paths = with nixGLPackages; [
-        nixGLIntel
-        nixVulkanIntel
-      ];
-    };
-
-  info = builtins.toJSON {
-    inherit
-      name
-      version
-      id
-      identity
-      launcher
-      groups
-      userns
-      net
-      dev
-      no_new_session
-      map_real_uid
-      direct_wayland
-      system_bus
-      gpu
-      ;
-
-    session_bus =
-      if session_bus != null then
-        (session_bus (extendSessionDefault id))
-      else
-        (extendSessionDefault id {
-          talk = [ ];
-          own = [ ];
-          call = { };
-          broadcast = { };
-        });
-
-    enablements = {
-      wayland = allow_wayland;
-      x11 = allow_x11;
-      dbus = allow_dbus;
-      pipewire = allow_audio;
-    };
-
-    mesa = if gpu then mesaWrappers else null;
-    nix_gl = if gpu then nixGL else null;
-    current_system = nixos.config.system.build.toplevel;
-    activation_package = homeManagerConfiguration.activationPackage;
-  };
-in
-
-stdenv.mkDerivation {
-  name = "${pname}.pkg";
-  inherit version;
-  __structuredAttrs = true;
-
-  nativeBuildInputs = [
-    zstd
-    nix
-    sqlite
-  ];
-
-  buildCommand = ''
-    NIX_ROOT="$(mktemp -d)"
-    export USER="nobody"
-
-    # create bootstrap store
-    bootstrapClosureInfo="${
-      closureInfo {
-        rootPaths = [
-          nix
-          nixos.config.system.build.toplevel
-        ];
-      }
-    }"
-    echo "copying bootstrap store paths..."
-    mkdir -p "$NIX_ROOT/nix/store"
-    xargs -n 1 -a "$bootstrapClosureInfo/store-paths" cp -at "$NIX_ROOT/nix/store/"
-    NIX_REMOTE="local?root=$NIX_ROOT" nix-store --load-db < "$bootstrapClosureInfo/registration"
-    NIX_REMOTE="local?root=$NIX_ROOT" nix-store --optimise
-    sqlite3 "$NIX_ROOT/nix/var/nix/db/db.sqlite" "UPDATE ValidPaths SET registrationTime = ''${SOURCE_DATE_EPOCH}"
-    chmod -R +r "$NIX_ROOT/nix/var"
-
-    # create binary cache
-    closureInfo="${
-      closureInfo {
-        rootPaths = [
-          homeManagerConfiguration.activationPackage
-          launcher
-        ]
-        ++ optionals gpu [
-          mesaWrappers
-          nixGL
-        ];
-      }
-    }"
-    echo "copying application paths..."
-    TMP_STORE="$(mktemp -d)"
-    mkdir -p "$TMP_STORE/nix/store"
-    xargs -n 1 -a "$closureInfo/store-paths" cp -at "$TMP_STORE/nix/store/"
-    NIX_REMOTE="local?root=$TMP_STORE" nix-store --load-db < "$closureInfo/registration"
-    sqlite3 "$TMP_STORE/nix/var/nix/db/db.sqlite" "UPDATE ValidPaths SET registrationTime = ''${SOURCE_DATE_EPOCH}"
-    NIX_REMOTE="local?root=$TMP_STORE" nix --offline --extra-experimental-features nix-command \
-        --verbose --log-format raw-with-logs \
-        copy --all --no-check-sigs --to \
-        "file://$NIX_ROOT/res?compression=zstd&compression-level=19&parallel-compression=true"
-
-    # package /etc
-    mkdir -p "$NIX_ROOT/etc"
-    tar -C "$NIX_ROOT/etc" -xf "${etc}/etc.tar"
-
-    # write metadata
-    cp "${writeText "bundle.json" info}" "$NIX_ROOT/bundle.json"
-
-    # create an intermediate file to improve zstd performance
-    INTER="$(mktemp)"
-    tar -C "$NIX_ROOT" -cf "$INTER" .
-    zstd -T0 -19 -fo "$out" "$INTER"
-  '';
-}

cmd/hpkg/main.go

@@ -1,335 +0,0 @@
-package main
-
-import (
-	"context"
-	"encoding/json"
-	"errors"
-	"log"
-	"os"
-	"os/signal"
-	"path"
-	"syscall"
-
-	"hakurei.app/command"
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
-	"hakurei.app/hst"
-	"hakurei.app/message"
-)
-
-var (
-	errSuccess = errors.New("success")
-)
-
-func main() {
-	log.SetPrefix("hpkg: ")
-	log.SetFlags(0)
-	msg := message.New(log.Default())
-
-	if err := os.Setenv("SHELL", pathShell.String()); err != nil {
-		log.Fatalf("cannot set $SHELL: %v", err)
-	}
-
-	if os.Geteuid() == 0 {
-		log.Fatal("this program must not run as root")
-	}
-
-	ctx, stop := signal.NotifyContext(context.Background(),
-		syscall.SIGINT, syscall.SIGTERM)
-	defer stop() // unreachable
-
-	var (
-		flagVerbose   bool
-		flagDropShell bool
-	)
-	c := command.New(os.Stderr, log.Printf, "hpkg", func([]string) error { msg.SwapVerbose(flagVerbose); return nil }).
-		Flag(&flagVerbose, "v", command.BoolFlag(false), "Print debug messages to the console").
-		Flag(&flagDropShell, "s", command.BoolFlag(false), "Drop to a shell in place of next hakurei action")
-
-	{
-		var (
-			flagDropShellActivate bool
-		)
-		c.NewCommand("install", "Install an application from its package", func(args []string) error {
-			if len(args) != 1 {
-				log.Println("invalid argument")
-				return syscall.EINVAL
-			}
-			pkgPath := args[0]
-			if !path.IsAbs(pkgPath) {
-				if dir, err := os.Getwd(); err != nil {
-					log.Printf("cannot get current directory: %v", err)
-					return err
-				} else {
-					pkgPath = path.Join(dir, pkgPath)
-				}
-			}
-
-			/*
-				Look up paths to programs started by hpkg.
-				This is done here to ease error handling as cleanup is not yet required.
-			*/
-
-			var (
-				_     = lookPath("zstd")
-				tar   = lookPath("tar")
-				chmod = lookPath("chmod")
-				rm    = lookPath("rm")
-			)
-
-			/*
-				Extract package and set up for cleanup.
-			*/
-
-			var workDir *check.Absolute
-			if p, err := os.MkdirTemp("", "hpkg.*"); err != nil {
-				log.Printf("cannot create temporary directory: %v", err)
-				return err
-			} else if workDir, err = check.NewAbs(p); err != nil {
-				log.Printf("invalid temporary directory: %v", err)
-				return err
-			}
-			cleanup := func() {
-				// should be faster than a native implementation
-				mustRun(msg, chmod, "-R", "+w", workDir.String())
-				mustRun(msg, rm, "-rf", workDir.String())
-			}
-			beforeRunFail.Store(&cleanup)
-
-			mustRun(msg, tar, "-C", workDir.String(), "-xf", pkgPath)
-
-			/*
-				Parse bundle and app metadata, do pre-install checks.
-			*/
-
-			bundle := loadAppInfo(path.Join(workDir.String(), "bundle.json"), cleanup)
-			pathSet := pathSetByApp(bundle.ID)
-
-			a := bundle
-			if s, err := os.Stat(pathSet.metaPath.String()); err != nil {
-				if !os.IsNotExist(err) {
-					cleanup()
-					log.Printf("cannot access %q: %v", pathSet.metaPath, err)
-					return err
-				}
-				// did not modify app, clean installation condition met later
-			} else if s.IsDir() {
-				cleanup()
-				log.Printf("metadata path %q is not a file", pathSet.metaPath)
-				return syscall.EBADMSG
-			} else {
-				a = loadAppInfo(pathSet.metaPath.String(), cleanup)
-				if a.ID != bundle.ID {
-					cleanup()
-					log.Printf("app %q claims to have identifier %q",
-						bundle.ID, a.ID)
-					return syscall.EBADE
-				}
-				// sec: should verify credentials
-			}
-
-			if a != bundle {
-				// do not try to re-install
-				if a.NixGL == bundle.NixGL &&
-					a.CurrentSystem == bundle.CurrentSystem &&
-					a.Launcher == bundle.Launcher &&
-					a.ActivationPackage == bundle.ActivationPackage {
-					cleanup()
-					log.Printf("package %q is identical to local application %q",
-						pkgPath, a.ID)
-					return errSuccess
-				}
-
-				// identity determines uid
-				if a.Identity != bundle.Identity {
-					cleanup()
-					log.Printf("package %q identity %d differs from installed %d",
-						pkgPath, bundle.Identity, a.Identity)
-					return syscall.EBADE
-				}
-
-				// sec: should compare version string
-				msg.Verbosef("installing application %q version %q over local %q",
-					bundle.ID, bundle.Version, a.Version)
-			} else {
-				msg.Verbosef("application %q clean installation", bundle.ID)
-				// sec: should install credentials
-			}
-
-			/*
-				Setup steps for files owned by the target user.
-			*/
-
-			withCacheDir(ctx, msg, "install", []string{
-				// export inner bundle path in the environment
-				"export BUNDLE=" + hst.PrivateTmp + "/bundle",
-				// replace inner /etc
-				"mkdir -p etc",
-				"chmod -R +w etc",
-				"rm -rf etc",
-				"cp -dRf $BUNDLE/etc etc",
-				// replace inner /nix
-				"mkdir -p nix",
-				"chmod -R +w nix",
-				"rm -rf nix",
-				"cp -dRf /nix nix",
-				// copy from binary cache
-				"nix copy --offline --no-check-sigs --all --from file://$BUNDLE/res --to $PWD",
-				// deduplicate nix store
-				"nix store --offline --store $PWD optimise",
-				// make cache directory world-readable for autoetc
-				"chmod 0755 .",
-			}, workDir, bundle, pathSet, flagDropShell, cleanup)
-
-			if bundle.GPU {
-				withCacheDir(ctx, msg, "mesa-wrappers", []string{
-					// link nixGL mesa wrappers
-					"mkdir -p nix/.nixGL",
-					"ln -s " + bundle.Mesa + "/bin/nixGLIntel nix/.nixGL/nixGL",
-					"ln -s " + bundle.Mesa + "/bin/nixVulkanIntel nix/.nixGL/nixVulkan",
-				}, workDir, bundle, pathSet, false, cleanup)
-			}
-
-			/*
-				Activate home-manager generation.
-			*/
-
-			withNixDaemon(ctx, msg, "activate", []string{
-				// clean up broken links
-				"mkdir -p .local/state/{nix,home-manager}",
-				"chmod -R +w .local/state/{nix,home-manager}",
-				"rm -rf .local/state/{nix,home-manager}",
-				// run activation script
-				bundle.ActivationPackage + "/activate",
-			}, false, func(config *hst.Config) *hst.Config { return config },
-				bundle, pathSet, flagDropShellActivate, cleanup)
-
-			/*
-				Installation complete. Write metadata to block re-installs or downgrades.
-			*/
-
-			// serialise metadata to ensure consistency
-			if f, err := os.OpenFile(pathSet.metaPath.String()+"~", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644); err != nil {
-				cleanup()
-				log.Printf("cannot create metadata file: %v", err)
-				return err
-			} else if err = json.NewEncoder(f).Encode(bundle); err != nil {
-				cleanup()
-				log.Printf("cannot write metadata: %v", err)
-				return err
-			} else if err = f.Close(); err != nil {
-				log.Printf("cannot close metadata file: %v", err)
-				// not fatal
-			}
-
-			if err := os.Rename(pathSet.metaPath.String()+"~", pathSet.metaPath.String()); err != nil {
-				cleanup()
-				log.Printf("cannot rename metadata file: %v", err)
-				return err
-			}
-
-			cleanup()
-			return errSuccess
-		}).
-			Flag(&flagDropShellActivate, "s", command.BoolFlag(false), "Drop to a shell on activation")
-	}
-
-	{
-		var (
-			flagDropShellNixGL bool
-			flagAutoDrivers    bool
-		)
-		c.NewCommand("start", "Start an application", func(args []string) error {
-			if len(args) < 1 {
-				log.Println("invalid argument")
-				return syscall.EINVAL
-			}
-
-			/*
-				Parse app metadata.
-			*/
-
-			id := args[0]
-			pathSet := pathSetByApp(id)
-			a := loadAppInfo(pathSet.metaPath.String(), func() {})
-			if a.ID != id {
-				log.Printf("app %q claims to have identifier %q", id, a.ID)
-				return syscall.EBADE
-			}
-
-			/*
-				Prepare nixGL.
-			*/
-
-			if a.GPU && flagAutoDrivers {
-				withNixDaemon(ctx, msg, "nix-gl", []string{
-					"mkdir -p /nix/.nixGL/auto",
-					"rm -rf /nix/.nixGL/auto",
-					"export NIXPKGS_ALLOW_UNFREE=1",
-					"nix build --impure " +
-						"--out-link /nix/.nixGL/auto/opengl " +
-						"--override-input nixpkgs path:/etc/nixpkgs " +
-						"path:" + a.NixGL,
-					"nix build --impure " +
-						"--out-link /nix/.nixGL/auto/vulkan " +
-						"--override-input nixpkgs path:/etc/nixpkgs " +
-						"path:" + a.NixGL + "#nixVulkanNvidia",
-				}, true, func(config *hst.Config) *hst.Config {
-					config.Container.Filesystem = append(config.Container.Filesystem, []hst.FilesystemConfigJSON{
-						{FilesystemConfig: &hst.FSBind{Source: fhs.AbsEtc.Append("resolv.conf"), Optional: true}},
-						{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("block"), Optional: true}},
-						{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("bus"), Optional: true}},
-						{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("class"), Optional: true}},
-						{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("dev"), Optional: true}},
-						{FilesystemConfig: &hst.FSBind{Source: fhs.AbsSys.Append("devices"), Optional: true}},
-					}...)
-					appendGPUFilesystem(config)
-					return config
-				}, a, pathSet, flagDropShellNixGL, func() {})
-			}
-
-			/*
-				Create app configuration.
-			*/
-
-			pathname := a.Launcher
-			argv := make([]string, 1, len(args))
-			if flagDropShell {
-				pathname = pathShell
-				argv[0] = bash
-			} else {
-				argv[0] = a.Launcher.String()
-			}
-			argv = append(argv, args[1:]...)
-			config := a.toHst(pathSet, pathname, argv, flagDropShell)
-
-			/*
-				Expose GPU devices.
-			*/
-
-			if a.GPU {
-				config.Container.Filesystem = append(config.Container.Filesystem,
-					hst.FilesystemConfigJSON{FilesystemConfig: &hst.FSBind{Source: pathSet.nixPath.Append(".nixGL"), Target: hst.AbsPrivateTmp.Append("nixGL")}})
-				appendGPUFilesystem(config)
-			}
-
-			/*
-				Spawn app.
-			*/
-
-			mustRunApp(ctx, msg, config, func() {})
-			return errSuccess
-		}).
-			Flag(&flagDropShellNixGL, "s", command.BoolFlag(false), "Drop to a shell on nixGL build").
-			Flag(&flagAutoDrivers, "auto-drivers", command.BoolFlag(false), "Attempt automatic opengl driver detection")
-	}
-
-	c.MustParse(os.Args[1:], func(err error) {
-		msg.Verbosef("command returned %v", err)
-		if errors.Is(err, errSuccess) {
-			msg.BeforeExit()
-			os.Exit(0)
-		}
-	})
-	log.Fatal("unreachable")
-}

cmd/hpkg/paths.go

@@ -1,117 +0,0 @@
-package main
-
-import (
-	"log"
-	"os"
-	"os/exec"
-	"strconv"
-	"sync/atomic"
-
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
-	"hakurei.app/hst"
-	"hakurei.app/message"
-)
-
-const bash = "bash"
-
-var (
-	dataHome *check.Absolute
-)
-
-func init() {
-	// dataHome
-	if a, err := check.NewAbs(os.Getenv("HAKUREI_DATA_HOME")); err == nil {
-		dataHome = a
-	} else {
-		dataHome = fhs.AbsVarLib.Append("hakurei/" + strconv.Itoa(os.Getuid()))
-	}
-}
-
-var (
-	pathBin = fhs.AbsRoot.Append("bin")
-
-	pathNix           = check.MustAbs("/nix/")
-	pathNixStore      = pathNix.Append("store/")
-	pathCurrentSystem = fhs.AbsRun.Append("current-system")
-	pathSwBin         = pathCurrentSystem.Append("sw/bin/")
-	pathShell         = pathSwBin.Append(bash)
-
-	pathData     = check.MustAbs("/data")
-	pathDataData = pathData.Append("data")
-)
-
-func lookPath(file string) string {
-	if p, err := exec.LookPath(file); err != nil {
-		log.Fatalf("%s: command not found", file)
-		return ""
-	} else {
-		return p
-	}
-}
-
-var beforeRunFail = new(atomic.Pointer[func()])
-
-func mustRun(msg message.Msg, name string, arg ...string) {
-	msg.Verbosef("spawning process: %q %q", name, arg)
-	cmd := exec.Command(name, arg...)
-	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-	if err := cmd.Run(); err != nil {
-		if f := beforeRunFail.Swap(nil); f != nil {
-			(*f)()
-		}
-		log.Fatalf("%s: %v", name, err)
-	}
-}
-
-type appPathSet struct {
-	// ${dataHome}/${id}
-	baseDir *check.Absolute
-	// ${baseDir}/app
-	metaPath *check.Absolute
-	// ${baseDir}/files
-	homeDir *check.Absolute
-	// ${baseDir}/cache
-	cacheDir *check.Absolute
-	// ${baseDir}/cache/nix
-	nixPath *check.Absolute
-}
-
-func pathSetByApp(id string) *appPathSet {
-	pathSet := new(appPathSet)
-	pathSet.baseDir = dataHome.Append(id)
-	pathSet.metaPath = pathSet.baseDir.Append("app")
-	pathSet.homeDir = pathSet.baseDir.Append("files")
-	pathSet.cacheDir = pathSet.baseDir.Append("cache")
-	pathSet.nixPath = pathSet.cacheDir.Append("nix")
-	return pathSet
-}
-
-func appendGPUFilesystem(config *hst.Config) {
-	config.Container.Filesystem = append(config.Container.Filesystem, []hst.FilesystemConfigJSON{
-		// flatpak commit 763a686d874dd668f0236f911de00b80766ffe79
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("dri"), Device: true, Optional: true}},
-		// mali
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("mali"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("mali0"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("umplock"), Device: true, Optional: true}},
-		// nvidia
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidiactl"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia-modeset"), Device: true, Optional: true}},
-		// nvidia OpenCL/CUDA
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia-uvm"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia-uvm-tools"), Device: true, Optional: true}},
-
-		// flatpak commit d2dff2875bb3b7e2cd92d8204088d743fd07f3ff
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia0"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia1"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia2"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia3"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia4"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia5"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia6"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia7"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia8"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia9"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia10"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia11"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia12"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia13"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia14"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia15"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia16"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia17"), Device: true, Optional: true}},
-		{FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia18"), Device: true, Optional: true}}, {FilesystemConfig: &hst.FSBind{Source: fhs.AbsDev.Append("nvidia19"), Device: true, Optional: true}},
-	}...)
-}

cmd/hpkg/proc.go

@@ -1,61 +0,0 @@
-package main
-
-import (
-	"context"
-	"encoding/json"
-	"errors"
-	"io"
-	"log"
-	"os"
-	"os/exec"
-
-	"hakurei.app/hst"
-	"hakurei.app/internal/info"
-	"hakurei.app/message"
-)
-
-var hakureiPathVal = info.MustHakureiPath().String()
-
-func mustRunApp(ctx context.Context, msg message.Msg, config *hst.Config, beforeFail func()) {
-	var (
-		cmd *exec.Cmd
-		st  io.WriteCloser
-	)
-
-	if r, w, err := os.Pipe(); err != nil {
-		beforeFail()
-		log.Fatalf("cannot pipe: %v", err)
-	} else {
-		if msg.IsVerbose() {
-			cmd = exec.CommandContext(ctx, hakureiPathVal, "-v", "app", "3")
-		} else {
-			cmd = exec.CommandContext(ctx, hakureiPathVal, "app", "3")
-		}
-		cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-		cmd.ExtraFiles = []*os.File{r}
-		st = w
-	}
-
-	go func() {
-		if err := json.NewEncoder(st).Encode(config); err != nil {
-			beforeFail()
-			log.Fatalf("cannot send configuration: %v", err)
-		}
-	}()
-
-	if err := cmd.Start(); err != nil {
-		beforeFail()
-		log.Fatalf("cannot start hakurei: %v", err)
-	}
-	if err := cmd.Wait(); err != nil {
-		var exitError *exec.ExitError
-		if errors.As(err, &exitError) {
-			beforeFail()
-			msg.BeforeExit()
-			os.Exit(exitError.ExitCode())
-		} else {
-			beforeFail()
-			log.Fatalf("cannot wait: %v", err)
-		}
-	}
-}

cmd/hpkg/test/configuration.nix

@@ -1,62 +0,0 @@
-{ pkgs, ... }:
-{
-  users.users = {
-    alice = {
-      isNormalUser = true;
-      description = "Alice Foobar";
-      password = "foobar";
-      uid = 1000;
-    };
-  };
-
-  home-manager.users.alice.home.stateVersion = "24.11";
-
-  # Automatically login on tty1 as a normal user:
-  services.getty.autologinUser = "alice";
-
-  environment = {
-    variables = {
-      SWAYSOCK = "/tmp/sway-ipc.sock";
-      WLR_RENDERER = "pixman";
-    };
-  };
-
-  # Automatically configure and start Sway when logging in on tty1:
-  programs.bash.loginShellInit = ''
-    if [ "$(tty)" = "/dev/tty1" ]; then
-      set -e
-
-      mkdir -p ~/.config/sway
-      (sed s/Mod4/Mod1/ /etc/sway/config &&
-      echo 'output * bg ${pkgs.nixos-artwork.wallpapers.simple-light-gray.gnomeFilePath} fill' &&
-      echo 'output Virtual-1 res 1680x1050') > ~/.config/sway/config
-
-      sway --validate
-      systemd-cat --identifier=session sway && touch /tmp/sway-exit-ok
-    fi
-  '';
-
-  programs.sway.enable = true;
-
-  virtualisation = {
-    diskSize = 6 * 1024;
-
-    qemu.options = [
-      # Need to switch to a different GPU driver than the default one (-vga std) so that Sway can launch:
-      "-vga none -device virtio-gpu-pci"
-
-      # Increase zstd performance:
-      "-smp 8"
-    ];
-  };
-
-  environment.hakurei = {
-    enable = true;
-    stateDir = "/var/lib/hakurei";
-    users.alice = 0;
-
-    extraHomeConfig = {
-      home.stateVersion = "23.05";
-    };
-  };
-}

cmd/hpkg/test/default.nix

@@ -1,34 +0,0 @@
-{
-  testers,
-  callPackage,
-
-  system,
-  self,
-}:
-let
-  buildPackage = self.buildPackage.${system};
-in
-testers.nixosTest {
-  name = "hpkg";
-  nodes.machine = {
-    environment.etc = {
-      "foot.pkg".source = callPackage ./foot.nix { inherit buildPackage; };
-    };
-
-    imports = [
-      ./configuration.nix
-
-      self.nixosModules.hakurei
-      self.inputs.home-manager.nixosModules.home-manager
-    ];
-  };
-
-  # adapted from nixos sway integration tests
-
-  # testScriptWithTypes:49: error: Cannot call function of unknown type
-  #           (machine.succeed if succeed else machine.execute)(
-  #           ^
-  # Found 1 error in 1 file (checked 1 source file)
-  skipTypeCheck = true;
-  testScript = builtins.readFile ./test.py;
-}

cmd/hpkg/test/foot.nix

@@ -1,48 +0,0 @@
-{
-  lib,
-  buildPackage,
-  foot,
-  wayland-utils,
-  inconsolata,
-}:
-
-buildPackage {
-  name = "foot";
-  inherit (foot) version;
-
-  identity = 2;
-  id = "org.codeberg.dnkl.foot";
-
-  modules = [
-    {
-      home.packages = [
-        foot
-
-        # For wayland-info:
-        wayland-utils
-      ];
-    }
-  ];
-
-  nixosModules = [
-    {
-      # To help with OCR:
-      environment.etc."xdg/foot/foot.ini".text = lib.generators.toINI { } {
-        main = {
-          font = "inconsolata:size=14";
-        };
-        colors = rec {
-          foreground = "000000";
-          background = "ffffff";
-          regular2 = foreground;
-        };
-      };
-
-      fonts.packages = [ inconsolata ];
-    }
-  ];
-
-  script = ''
-    exec foot "$@"
-  '';
-}

cmd/hpkg/test/test.py

@@ -1,110 +0,0 @@
-import json
-import shlex
-
-q = shlex.quote
-NODE_GROUPS = ["nodes", "floating_nodes"]
-
-
-def swaymsg(command: str = "", succeed=True, type="command"):
-    assert command != "" or type != "command", "Must specify command or type"
-    shell = q(f"swaymsg -t {q(type)} -- {q(command)}")
-    with machine.nested(
-            f"sending swaymsg {shell!r}" + " (allowed to fail)" * (not succeed)
-    ):
-        ret = (machine.succeed if succeed else machine.execute)(
-            f"su - alice -c {shell}"
-        )
-
-    # execute also returns a status code, but disregard.
-    if not succeed:
-        _, ret = ret
-
-    if not succeed and not ret:
-        return None
-
-    parsed = json.loads(ret)
-    return parsed
-
-
-def walk(tree):
-    yield tree
-    for group in NODE_GROUPS:
-        for node in tree.get(group, []):
-            yield from walk(node)
-
-
-def wait_for_window(pattern):
-    def func(last_chance):
-        nodes = (node["name"] for node in walk(swaymsg(type="get_tree")))
-
-        if last_chance:
-            nodes = list(nodes)
-            machine.log(f"Last call! Current list of windows: {nodes}")
-
-        return any(pattern in name for name in nodes)
-
-    retry(func)
-
-
-def collect_state_ui(name):
-    swaymsg(f"exec hakurei ps > '/tmp/{name}.ps'")
-    machine.copy_from_vm(f"/tmp/{name}.ps", "")
-    swaymsg(f"exec hakurei --json ps > '/tmp/{name}.json'")
-    machine.copy_from_vm(f"/tmp/{name}.json", "")
-    machine.screenshot(name)
-
-
-def check_state(name, enablements):
-    instances = json.loads(machine.succeed("sudo -u alice -i XDG_RUNTIME_DIR=/run/user/1000 hakurei --json ps"))
-    if len(instances) != 1:
-        raise Exception(f"unexpected state length {len(instances)}")
-    instance = instances[0]
-
-    if len(instance['container']['args']) != 1 or not (instance['container']['args'][0].startswith("/nix/store/")) or f"hakurei-{name}-" not in (instance['container']['args'][0]):
-        raise Exception(f"unexpected args {instance['container']['args']}")
-
-    if instance['enablements'] != enablements:
-        raise Exception(f"unexpected enablements {instance['enablements']}")
-
-
-start_all()
-machine.wait_for_unit("multi-user.target")
-
-# To check hakurei's version:
-print(machine.succeed("sudo -u alice -i hakurei version"))
-
-# Wait for Sway to complete startup:
-machine.wait_for_file("/run/user/1000/wayland-1")
-machine.wait_for_file("/tmp/sway-ipc.sock")
-
-# Prepare hpkg directory:
-machine.succeed("install -dm 0700 -o alice -g users /var/lib/hakurei/1000")
-
-# Install hpkg app:
-swaymsg("exec hpkg -v install /etc/foot.pkg && touch /tmp/hpkg-install-ok")
-machine.wait_for_file("/tmp/hpkg-install-ok")
-
-# Start app (foot) with Wayland enablement:
-swaymsg("exec hpkg -v start org.codeberg.dnkl.foot")
-wait_for_window("hakurei@machine-foot")
-machine.send_chars("clear; wayland-info && touch /tmp/success-client\n")
-machine.wait_for_file("/tmp/hakurei.0/tmpdir/2/success-client")
-collect_state_ui("app_wayland")
-check_state("foot", {"wayland": True, "dbus": True, "pipewire": True})
-# Verify acl on XDG_RUNTIME_DIR:
-print(machine.succeed("getfacl --absolute-names --omit-header --numeric /tmp/hakurei.0/runtime | grep 10002"))
-machine.send_chars("exit\n")
-machine.wait_until_fails("pgrep foot")
-# Verify acl cleanup on XDG_RUNTIME_DIR:
-machine.wait_until_fails("getfacl --absolute-names --omit-header --numeric /tmp/hakurei.0/runtime | grep 10002")
-
-# Exit Sway and verify process exit status 0:
-swaymsg("exit", succeed=False)
-machine.wait_for_file("/tmp/sway-exit-ok")
-
-# Print hakurei share and rundir contents:
-print(machine.succeed("find /tmp/hakurei.0 "
-    + "-path '/tmp/hakurei.0/runtime/*/*' -prune -o "
-    + "-path '/tmp/hakurei.0/tmpdir/*/*' -prune -o "
-    + "-print"))
-print(machine.fail("ls /run/user/1000/hakurei"))

cmd/hpkg/with.go

@@ -1,130 +0,0 @@
-package main
-
-import (
-	"context"
-	"os"
-	"strings"
-
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
-	"hakurei.app/hst"
-	"hakurei.app/message"
-)
-
-func withNixDaemon(
-	ctx context.Context,
-	msg message.Msg,
-	action string, command []string, net bool, updateConfig func(config *hst.Config) *hst.Config,
-	app *appInfo, pathSet *appPathSet, dropShell bool, beforeFail func(),
-) {
-	flags := hst.FMultiarch | hst.FUserns // nix sandbox requires userns
-	if net {
-		flags |= hst.FHostNet
-	}
-	if dropShell {
-		flags |= hst.FTty
-	}
-
-	mustRunAppDropShell(ctx, msg, updateConfig(&hst.Config{
-		ID: app.ID,
-
-		ExtraPerms: []hst.ExtraPermConfig{
-			{Path: dataHome, Execute: true},
-			{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
-		},
-
-		Identity: app.Identity,
-
-		Container: &hst.ContainerConfig{
-			Hostname: formatHostname(app.Name) + "-" + action,
-
-			Filesystem: []hst.FilesystemConfigJSON{
-				{FilesystemConfig: &hst.FSBind{Target: fhs.AbsEtc, Source: pathSet.cacheDir.Append("etc"), Special: true}},
-				{FilesystemConfig: &hst.FSBind{Source: pathSet.nixPath, Target: pathNix, Write: true}},
-				{FilesystemConfig: &hst.FSLink{Target: pathCurrentSystem, Linkname: app.CurrentSystem.String()}},
-				{FilesystemConfig: &hst.FSLink{Target: pathBin, Linkname: pathSwBin.String()}},
-				{FilesystemConfig: &hst.FSLink{Target: fhs.AbsUsrBin, Linkname: pathSwBin.String()}},
-				{FilesystemConfig: &hst.FSBind{Target: pathDataData.Append(app.ID), Source: pathSet.homeDir, Write: true, Ensure: true}},
-			},
-
-			Username: "hakurei",
-			Shell:    pathShell,
-			Home:     pathDataData.Append(app.ID),
-
-			Path: pathShell,
-			Args: []string{bash, "-lc", "rm -f /nix/var/nix/daemon-socket/socket && " +
-				// start nix-daemon
-				"nix-daemon --store / & " +
-				// wait for socket to appear
-				"(while [ ! -S /nix/var/nix/daemon-socket/socket ]; do sleep 0.01; done) && " +
-				// create directory so nix stops complaining
-				"mkdir -p /nix/var/nix/profiles/per-user/root/channels && " +
-				strings.Join(command, " && ") +
-				// terminate nix-daemon
-				" && pkill nix-daemon",
-			},
-
-			Flags: flags,
-		},
-	}), dropShell, beforeFail)
-}
-
-func withCacheDir(
-	ctx context.Context,
-	msg message.Msg,
-	action string, command []string, workDir *check.Absolute,
-	app *appInfo, pathSet *appPathSet, dropShell bool, beforeFail func(),
-) {
-	flags := hst.FMultiarch
-	if dropShell {
-		flags |= hst.FTty
-	}
-
-	mustRunAppDropShell(ctx, msg, &hst.Config{
-		ID: app.ID,
-
-		ExtraPerms: []hst.ExtraPermConfig{
-			{Path: dataHome, Execute: true},
-			{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
-			{Path: workDir, Execute: true},
-		},
-
-		Identity: app.Identity,
-
-		Container: &hst.ContainerConfig{
-			Hostname: formatHostname(app.Name) + "-" + action,
-
-			Filesystem: []hst.FilesystemConfigJSON{
-				{FilesystemConfig: &hst.FSBind{Target: fhs.AbsEtc, Source: workDir.Append(fhs.Etc), Special: true}},
-				{FilesystemConfig: &hst.FSBind{Source: workDir.Append("nix"), Target: pathNix}},
-				{FilesystemConfig: &hst.FSLink{Target: pathCurrentSystem, Linkname: app.CurrentSystem.String()}},
-				{FilesystemConfig: &hst.FSLink{Target: pathBin, Linkname: pathSwBin.String()}},
-				{FilesystemConfig: &hst.FSLink{Target: fhs.AbsUsrBin, Linkname: pathSwBin.String()}},
-				{FilesystemConfig: &hst.FSBind{Source: workDir, Target: hst.AbsPrivateTmp.Append("bundle")}},
-				{FilesystemConfig: &hst.FSBind{Target: pathDataData.Append(app.ID, "cache"), Source: pathSet.cacheDir, Write: true, Ensure: true}},
-			},
-
-			Username: "nixos",
-			Shell:    pathShell,
-			Home:     pathDataData.Append(app.ID, "cache"),
-
-			Path: pathShell,
-			Args: []string{bash, "-lc", strings.Join(command, " && ")},
-
-			Flags: flags,
-		},
-	}, dropShell, beforeFail)
-}
-
-func mustRunAppDropShell(ctx context.Context, msg message.Msg, config *hst.Config, dropShell bool, beforeFail func()) {
-	if dropShell {
-		if config.Container != nil {
-			config.Container.Args = []string{bash, "-l"}
-		}
-		mustRunApp(ctx, msg, config, beforeFail)
-		beforeFail()
-		msg.BeforeExit()
-		os.Exit(0)
-	}
-	mustRunApp(ctx, msg, config, beforeFail)
-}

cmd/mbf/main.go

@@ -4,17 +4,26 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"os/signal"
 	"path/filepath"
 	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
 	"syscall"
+	"time"
 	"unique"
 
 	"hakurei.app/command"
 	"hakurei.app/container"
 	"hakurei.app/container/check"
+	"hakurei.app/container/fhs"
+	"hakurei.app/container/seccomp"
+	"hakurei.app/container/std"
 	"hakurei.app/internal/pkg"
 	"hakurei.app/internal/rosa"
 	"hakurei.app/message"
@@ -51,10 +60,16 @@ func main() {
 		flagCures  int
 		flagBase   string
 		flagTShift int
+		flagIdle   bool
 	)
 	c := command.New(os.Stderr, log.Printf, "mbf", func([]string) (err error) {
 		msg.SwapVerbose(!flagQuiet)
 
+		flagBase = os.ExpandEnv(flagBase)
+		if flagBase == "" {
+			flagBase = "cache"
+		}
+
 		var base *check.Absolute
 		if flagBase, err = filepath.Abs(flagBase); err != nil {
 			return
@@ -70,6 +85,11 @@ func main() {
 				cache.SetThreshold(1 << flagTShift)
 			}
 		}
+
+		if flagIdle {
+			pkg.SetSchedIdle = true
+		}
+
 		return
 	}).Flag(
 		&flagQuiet,
@@ -81,12 +101,16 @@ func main() {
 		"Maximum number of dependencies to cure at any given time",
 	).Flag(
 		&flagBase,
-		"d", command.StringFlag("cache"),
+		"d", command.StringFlag("$MBF_CACHE_DIR"),
 		"Directory to store cured artifacts",
 	).Flag(
 		&flagTShift,
 		"tshift", command.IntFlag(-1),
 		"Dependency graph size exponent, to the power of 2",
+	).Flag(
+		&flagIdle,
+		"sched-idle", command.BoolFlag(false),
+		"Set SCHED_IDLE scheduling policy",
 	)
 
 	{
@@ -109,50 +133,309 @@ func main() {
 		)
 	}
 
-	c.NewCommand(
-		"stage3",
-		"Check for toolchain 3-stage non-determinism",
-		func(args []string) (err error) {
-			_, _, _, stage1 := (rosa.Std - 2).NewLLVM()
-			_, _, _, stage2 := (rosa.Std - 1).NewLLVM()
-			_, _, _, stage3 := rosa.Std.NewLLVM()
-			var (
-				pathname *check.Absolute
-				checksum [2]unique.Handle[pkg.Checksum]
-			)
-
-			if pathname, _, err = cache.Cure(stage1); err != nil {
-				return err
-			}
-			log.Println("stage1:", pathname)
-
-			if pathname, checksum[0], err = cache.Cure(stage2); err != nil {
-				return err
-			}
-			log.Println("stage2:", pathname)
-			if pathname, checksum[1], err = cache.Cure(stage3); err != nil {
-				return err
-			}
-			log.Println("stage3:", pathname)
-
-			if checksum[0] != checksum[1] {
-				err = &pkg.ChecksumMismatchError{
-					Got:  checksum[0].Value(),
-					Want: checksum[1].Value(),
+	{
+		var (
+			flagStatus bool
+			flagReport string
+		)
+		c.NewCommand(
+			"info",
+			"Display out-of-band metadata of an artifact",
+			func(args []string) (err error) {
+				if len(args) == 0 {
+					return errors.New("info requires at least 1 argument")
 				}
-			} else {
-				log.Println(
-					"stage2 is identical to stage3",
-					"("+pkg.Encode(checksum[0].Value())+")",
-				)
+
+				var r *rosa.Report
+				if flagReport != "" {
+					if r, err = rosa.OpenReport(flagReport); err != nil {
+						return err
+					}
+					defer func() {
+						if closeErr := r.Close(); err == nil {
+							err = closeErr
+						}
+					}()
+					defer r.HandleAccess(&err)()
+				}
+
+				for i, name := range args {
+					if p, ok := rosa.ResolveName(name); !ok {
+						return fmt.Errorf("unknown artifact %q", name)
+					} else {
+						var suffix string
+						if version := rosa.Std.Version(p); version != rosa.Unversioned {
+							suffix += "-" + version
+						}
+						fmt.Println("name        : " + name + suffix)
+
+						meta := rosa.GetMetadata(p)
+						fmt.Println("description : " + meta.Description)
+						if meta.Website != "" {
+							fmt.Println("website     : " +
+								strings.TrimSuffix(meta.Website, "/"))
+						}
+						if len(meta.Dependencies) > 0 {
+							fmt.Print("depends on  :")
+							for _, d := range meta.Dependencies {
+								s := rosa.GetMetadata(d).Name
+								if version := rosa.Std.Version(d); version != rosa.Unversioned {
+									s += "-" + version
+								}
+								fmt.Print(" " + s)
+							}
+							fmt.Println()
+						}
+
+						const statusPrefix = "status      : "
+						if flagStatus {
+							if r == nil {
+								var f io.ReadSeekCloser
+								f, err = cache.OpenStatus(rosa.Std.Load(p))
+								if err != nil {
+									if errors.Is(err, os.ErrNotExist) {
+										fmt.Println(
+											statusPrefix + "not yet cured",
+										)
+									} else {
+										return
+									}
+								} else {
+									fmt.Print(statusPrefix)
+									_, err = io.Copy(os.Stdout, f)
+									if err = errors.Join(err, f.Close()); err != nil {
+										return
+									}
+								}
+							} else {
+								status, n := r.ArtifactOf(cache.Ident(rosa.Std.Load(p)))
+								if status == nil {
+									fmt.Println(
+										statusPrefix + "not in report",
+									)
+								} else {
+									fmt.Println("size        :", n)
+									fmt.Print(statusPrefix)
+									if _, err = os.Stdout.Write(status); err != nil {
+										return
+									}
+								}
+							}
+						}
+
+						if i != len(args)-1 {
+							fmt.Println()
+						}
+					}
+				}
+				return nil
+			},
+		).
+			Flag(
+				&flagStatus,
+				"status", command.BoolFlag(false),
+				"Display cure status if available",
+			).
+			Flag(
+				&flagReport,
+				"report", command.StringFlag(""),
+				"Load cure status from this report file instead of cache",
+			)
+	}
+
+	c.NewCommand(
+		"report",
+		"Generate an artifact cure report for the current cache",
+		func(args []string) (err error) {
+			var w *os.File
+			switch len(args) {
+			case 0:
+				w = os.Stdout
+
+			case 1:
+				if w, err = os.OpenFile(
+					args[0],
+					os.O_CREATE|os.O_EXCL|syscall.O_WRONLY,
+					0400,
+				); err != nil {
+					return
+				}
+				defer func() {
+					closeErr := w.Close()
+					if err == nil {
+						err = closeErr
+					}
+				}()
+
+			default:
+				return errors.New("report requires 1 argument")
 			}
-			return
+
+			if container.Isatty(int(w.Fd())) {
+				return errors.New("output appears to be a terminal")
+			}
+			return rosa.WriteReport(msg, w, cache)
 		},
 	)
 
+	{
+		var flagJobs int
+		c.NewCommand("updates", command.UsageInternal, func([]string) error {
+			var (
+				errsMu sync.Mutex
+				errs   []error
+
+				n atomic.Uint64
+			)
+
+			w := make(chan rosa.PArtifact)
+			var wg sync.WaitGroup
+			for range max(flagJobs, 1) {
+				wg.Go(func() {
+					for p := range w {
+						meta := rosa.GetMetadata(p)
+						if meta.ID == 0 {
+							continue
+						}
+
+						v, err := meta.GetVersions(ctx)
+						if err != nil {
+							errsMu.Lock()
+							errs = append(errs, err)
+							errsMu.Unlock()
+							continue
+						}
+
+						if current, latest :=
+							rosa.Std.Version(p),
+							meta.GetLatest(v); current != latest {
+
+							n.Add(1)
+							log.Printf("%s %s < %s", meta.Name, current, latest)
+							continue
+						}
+
+						msg.Verbosef("%s is up to date", meta.Name)
+					}
+				})
+			}
+
+		done:
+			for i := range rosa.PresetEnd {
+				select {
+				case w <- rosa.PArtifact(i):
+					break
+				case <-ctx.Done():
+					break done
+				}
+			}
+			close(w)
+			wg.Wait()
+
+			if v := n.Load(); v > 0 {
+				errs = append(errs, errors.New(strconv.Itoa(int(v))+
+					" package(s) are out of date"))
+			}
+			return errors.Join(errs...)
+		}).
+			Flag(
+				&flagJobs,
+				"j", command.IntFlag(32),
+				"Maximum number of simultaneous connections",
+			)
+	}
+
 	{
 		var (
-			flagDump string
+			flagGentoo   string
+			flagChecksum string
+
+			flagStage0 bool
+		)
+		c.NewCommand(
+			"stage3",
+			"Check for toolchain 3-stage non-determinism",
+			func(args []string) (err error) {
+				t := rosa.Std
+				if flagGentoo != "" {
+					t -= 3 // magic number to discourage misuse
+
+					var checksum pkg.Checksum
+					if len(flagChecksum) != 0 {
+						if err = pkg.Decode(&checksum, flagChecksum); err != nil {
+							return
+						}
+					}
+					rosa.SetGentooStage3(flagGentoo, checksum)
+				}
+
+				_, _, _, stage1 := (t - 2).NewLLVM()
+				_, _, _, stage2 := (t - 1).NewLLVM()
+				_, _, _, stage3 := t.NewLLVM()
+				var (
+					pathname *check.Absolute
+					checksum [2]unique.Handle[pkg.Checksum]
+				)
+
+				if pathname, _, err = cache.Cure(stage1); err != nil {
+					return err
+				}
+				log.Println("stage1:", pathname)
+
+				if pathname, checksum[0], err = cache.Cure(stage2); err != nil {
+					return err
+				}
+				log.Println("stage2:", pathname)
+				if pathname, checksum[1], err = cache.Cure(stage3); err != nil {
+					return err
+				}
+				log.Println("stage3:", pathname)
+
+				if checksum[0] != checksum[1] {
+					err = &pkg.ChecksumMismatchError{
+						Got:  checksum[0].Value(),
+						Want: checksum[1].Value(),
+					}
+				} else {
+					log.Println(
+						"stage2 is identical to stage3",
+						"("+pkg.Encode(checksum[0].Value())+")",
+					)
+				}
+
+				if flagStage0 {
+					if pathname, _, err = cache.Cure(
+						t.Load(rosa.Stage0),
+					); err != nil {
+						return err
+					}
+					log.Println(pathname)
+				}
+
+				return
+			},
+		).
+			Flag(
+				&flagGentoo,
+				"gentoo", command.StringFlag(""),
+				"Bootstrap from a Gentoo stage3 tarball",
+			).
+			Flag(
+				&flagChecksum,
+				"checksum", command.StringFlag(""),
+				"Checksum of Gentoo stage3 tarball",
+			).
+			Flag(
+				&flagStage0,
+				"stage0", command.BoolFlag(false),
+				"Create bootstrap stage0 tarball",
+			)
+	}
+
+	{
+		var (
+			flagDump   string
+			flagExport string
 		)
 		c.NewCommand(
 			"cure",
@@ -162,13 +445,37 @@ func main() {
 					return errors.New("cure requires 1 argument")
 				}
 				if p, ok := rosa.ResolveName(args[0]); !ok {
-					return fmt.Errorf("unsupported artifact %q", args[0])
+					return fmt.Errorf("unknown artifact %q", args[0])
 				} else if flagDump == "" {
 					pathname, _, err := cache.Cure(rosa.Std.Load(p))
-					if err == nil {
-						log.Println(pathname)
+					if err != nil {
+						return err
 					}
-					return err
+					log.Println(pathname)
+
+					if flagExport != "" {
+						msg.Verbosef("exporting %s to %s...", args[0], flagExport)
+
+						var f *os.File
+						if f, err = os.OpenFile(
+							flagExport,
+							os.O_WRONLY|os.O_CREATE|os.O_EXCL,
+							0400,
+						); err != nil {
+							return err
+						} else if _, err = pkg.Flatten(
+							os.DirFS(pathname.String()),
+							".",
+							f,
+						); err != nil {
+							_ = f.Close()
+							return err
+						} else if err = f.Close(); err != nil {
+							return err
+						}
+					}
+
+					return nil
 				} else {
 					f, err := os.OpenFile(
 						flagDump,
@@ -192,13 +499,173 @@ func main() {
 				&flagDump,
 				"dump", command.StringFlag(""),
 				"Write IR to specified pathname and terminate",
+			).
+			Flag(
+				&flagExport,
+				"export", command.StringFlag(""),
+				"Export cured artifact to specified pathname",
 			)
 	}
 
+	{
+		var (
+			flagNet     bool
+			flagSession bool
+
+			flagWithToolchain bool
+		)
+		c.NewCommand(
+			"shell",
+			"Interactive shell in the specified Rosa OS environment",
+			func(args []string) error {
+				presets := make([]rosa.PArtifact, len(args))
+				for i, arg := range args {
+					p, ok := rosa.ResolveName(arg)
+					if !ok {
+						return fmt.Errorf("unknown artifact %q", arg)
+					}
+					presets[i] = p
+				}
+				root := make(rosa.Collect, 0, 6+len(args))
+				root = rosa.Std.AppendPresets(root, presets...)
+
+				if flagWithToolchain {
+					musl, compilerRT, runtimes, clang := (rosa.Std - 1).NewLLVM()
+					root = append(root, musl, compilerRT, runtimes, clang)
+				} else {
+					root = append(root, rosa.Std.Load(rosa.Musl))
+				}
+				root = append(root,
+					rosa.Std.Load(rosa.Mksh),
+					rosa.Std.Load(rosa.Toybox),
+				)
+
+				if _, _, err := cache.Cure(&root); err == nil {
+					return errors.New("unreachable")
+				} else if !errors.Is(err, rosa.Collected{}) {
+					return err
+				}
+
+				type cureRes struct {
+					pathname *check.Absolute
+					checksum unique.Handle[pkg.Checksum]
+				}
+				cured := make(map[pkg.Artifact]cureRes)
+				for _, a := range root {
+					pathname, checksum, err := cache.Cure(a)
+					if err != nil {
+						return err
+					}
+					cured[a] = cureRes{pathname, checksum}
+				}
+
+				layers := pkg.PromoteLayers(root, func(a pkg.Artifact) (
+					*check.Absolute,
+					unique.Handle[pkg.Checksum],
+				) {
+					res := cured[a]
+					return res.pathname, res.checksum
+				}, func(i int, d pkg.Artifact) {
+					r := pkg.Encode(cache.Ident(d).Value())
+					if s, ok := d.(fmt.Stringer); ok {
+						if name := s.String(); name != "" {
+							r += "-" + name
+						}
+					}
+					msg.Verbosef("promoted layer %d as %s", i, r)
+				})
+
+				z := container.New(ctx, msg)
+				z.WaitDelay = 3 * time.Second
+				z.SeccompPresets = pkg.SeccompPresets
+				z.SeccompFlags |= seccomp.AllowMultiarch
+				z.ParentPerm = 0700
+				z.HostNet = flagNet
+				z.RetainSession = flagSession
+				z.Hostname = "localhost"
+				z.Uid, z.Gid = (1<<10)-1, (1<<10)-1
+				z.Stdin, z.Stdout, z.Stderr = os.Stdin, os.Stdout, os.Stderr
+
+				var tempdir *check.Absolute
+				if s, err := filepath.Abs(os.TempDir()); err != nil {
+					return err
+				} else if tempdir, err = check.NewAbs(s); err != nil {
+					return err
+				}
+
+				z.Dir = fhs.AbsRoot
+				z.Env = []string{
+					"SHELL=/system/bin/mksh",
+					"PATH=/system/bin",
+					"HOME=/",
+				}
+				z.Path = rosa.AbsSystem.Append("bin", "mksh")
+				z.Args = []string{"mksh"}
+				z.
+					OverlayEphemeral(fhs.AbsRoot, layers...).
+					Place(
+						fhs.AbsEtc.Append("hosts"),
+						[]byte("127.0.0.1 localhost\n"),
+					).
+					Place(
+						fhs.AbsEtc.Append("passwd"),
+						[]byte("media_rw:x:1023:1023::/:/system/bin/sh\n"+
+							"nobody:x:65534:65534::/proc/nonexistent:/system/bin/false\n"),
+					).
+					Place(
+						fhs.AbsEtc.Append("group"),
+						[]byte("media_rw:x:1023:\nnobody:x:65534:\n"),
+					).
+					Bind(tempdir, fhs.AbsTmp, std.BindWritable).
+					Proc(fhs.AbsProc).Dev(fhs.AbsDev, true)
+
+				if err := z.Start(); err != nil {
+					return err
+				}
+				if err := z.Serve(); err != nil {
+					return err
+				}
+				return z.Wait()
+			},
+		).
+			Flag(
+				&flagNet,
+				"net", command.BoolFlag(false),
+				"Share host net namespace",
+			).
+			Flag(
+				&flagSession,
+				"session", command.BoolFlag(false),
+				"Retain session",
+			).
+			Flag(
+				&flagWithToolchain,
+				"with-toolchain", command.BoolFlag(false),
+				"Include the stage3 LLVM toolchain",
+			)
+
+	}
+
+	c.Command(
+		"help",
+		"Show this help message",
+		func([]string) error { c.PrintHelp(); return nil },
+	)
+
 	c.MustParse(os.Args[1:], func(err error) {
 		if cache != nil {
 			cache.Close()
 		}
-		log.Fatal(err)
+		if w, ok := err.(interface{ Unwrap() []error }); !ok {
+			log.Fatal(err)
+		} else {
+			errs := w.Unwrap()
+			for i, e := range errs {
+				if i == len(errs)-1 {
+					log.Fatal(e)
+				}
+				log.Println(e)
+			}
+		}
 	})
 }

cmd/sharefs/fuse.go

@@ -33,6 +33,7 @@ import (
 
 	"hakurei.app/container"
 	"hakurei.app/container/check"
+	"hakurei.app/container/fhs"
 	"hakurei.app/container/std"
 	"hakurei.app/hst"
 	"hakurei.app/internal/helper/proc"
@@ -441,12 +442,7 @@ func _main(s ...string) (exitCode int) {
 		// keep fuse_parse_cmdline happy in the container
 		z.Tmpfs(check.MustAbs(container.Nonexistent), 1<<10, 0755)
 
-		if a, err := check.NewAbs(container.MustExecutable(msg)); err != nil {
-			log.Println(err)
-			return 5
-		} else {
-			z.Path = a
-		}
+		z.Path = fhs.AbsProcSelfExe
 		z.Args = s
 		z.ForwardCancel = true
 		z.SeccompPresets |= std.PresetStrict

container/autoetc.go

@@ -10,8 +10,7 @@ import (
 
 func init() { gob.Register(new(AutoEtcOp)) }
 
-// Etc appends an [Op] that expands host /etc into a toplevel symlink mirror with /etc semantics.
-// This is not a generic setup op. It is implemented here to reduce ipc overhead.
+// Etc is a helper for appending [AutoEtcOp] to [Ops].
 func (f *Ops) Etc(host *check.Absolute, prefix string) *Ops {
 	e := &AutoEtcOp{prefix}
 	f.Mkdir(fhs.AbsEtc, 0755)
@@ -20,6 +19,9 @@ func (f *Ops) Etc(host *check.Absolute, prefix string) *Ops {
 	return f
 }
 
+// AutoEtcOp expands host /etc into a toplevel symlink mirror with /etc semantics.
+//
+// This is not a generic setup op. It is implemented here to reduce ipc overhead.
 type AutoEtcOp struct{ Prefix string }
 
 func (e *AutoEtcOp) Valid() bool                                { return e != nil }

container/autoroot.go

@@ -11,13 +11,15 @@ import (
 
 func init() { gob.Register(new(AutoRootOp)) }
 
-// Root appends an [Op] that expands a directory into a toplevel bind mount mirror on container root.
-// This is not a generic setup op. It is implemented here to reduce ipc overhead.
+// Root is a helper for appending [AutoRootOp] to [Ops].
 func (f *Ops) Root(host *check.Absolute, flags int) *Ops {
 	*f = append(*f, &AutoRootOp{host, flags, nil})
 	return f
 }
 
+// AutoRootOp expands a directory into a toplevel bind mount mirror on container root.
+//
+// This is not a generic setup op. It is implemented here to reduce ipc overhead.
 type AutoRootOp struct {
 	Host *check.Absolute
 	// passed through to bindMount

container/capability.go

@@ -50,10 +50,16 @@ func capset(hdrp *capHeader, datap *[2]capData) error {
 }
 
 // capBoundingSetDrop drops a capability from the calling thread's capability bounding set.
-func capBoundingSetDrop(cap uintptr) error { return Prctl(syscall.PR_CAPBSET_DROP, cap, 0) }
+func capBoundingSetDrop(cap uintptr) error {
+	return Prctl(syscall.PR_CAPBSET_DROP, cap, 0)
+}
 
 // capAmbientClearAll clears the ambient capability set of the calling thread.
-func capAmbientClearAll() error { return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0) }
+func capAmbientClearAll() error {
+	return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0)
+}
 
 // capAmbientRaise adds to the ambient capability set of the calling thread.
-func capAmbientRaise(cap uintptr) error { return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap) }
+func capAmbientRaise(cap uintptr) error {
+	return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap)
+}

container/check/overlay.go

@@ -11,7 +11,8 @@ const (
 	SpecialOverlayPath = ":"
 )
 
-// EscapeOverlayDataSegment escapes a string for formatting into the data argument of an overlay mount call.
+// EscapeOverlayDataSegment escapes a string for formatting into the data
+// argument of an overlay mount system call.
 func EscapeOverlayDataSegment(s string) string {
 	if s == "" {
 		return ""

container/container.go

@@ -1,4 +1,5 @@
-// Package container implements unprivileged Linux containers with built-in support for syscall filtering.
+// Package container implements unprivileged Linux containers with built-in
+// support for syscall filtering.
 package container
 
 import (
@@ -37,24 +38,34 @@ type (
 	Container struct {
 		// Whether the container init should stay alive after its parent terminates.
 		AllowOrphan bool
+		// Whether to set SchedPolicy and SchedPriority via sched_setscheduler(2).
+		SetScheduler bool
+		// Scheduling policy to set via sched_setscheduler(2).
+		SchedPolicy std.SchedPolicy
+		// Scheduling priority to set via sched_setscheduler(2). The zero value
+		// implies the minimum value supported by the current SchedPolicy.
+		SchedPriority std.Int
 		// Cgroup fd, nil to disable.
 		Cgroup *int
-		// ExtraFiles passed through to initial process in the container,
-		// with behaviour identical to its [exec.Cmd] counterpart.
+		// ExtraFiles passed through to initial process in the container, with
+		// behaviour identical to its [exec.Cmd] counterpart.
 		ExtraFiles []*os.File
 
-		// param pipe for shim and init
+		// Write end of a pipe connected to the init to deliver [Params].
 		setup *os.File
-		// cancels cmd
+		// Cancels the context passed to the underlying cmd.
 		cancel context.CancelFunc
-		// closed after Wait returns
+		// Closed after Wait returns. Keeps the spawning thread alive.
 		wait chan struct{}
 
 		Stdin  io.Reader
 		Stdout io.Writer
 		Stderr io.Writer
 
-		Cancel    func(cmd *exec.Cmd) error
+		// Custom cancellation behaviour for the underlying [exec.Cmd]. Must
+		// deliver [CancelSignal] before returning.
+		Cancel func(cmd *exec.Cmd) error
+		// Copied to the underlying [exec.Cmd].
 		WaitDelay time.Duration
 
 		cmd *exec.Cmd
@@ -283,7 +294,11 @@ func (p *Container) Start() error {
 
 	// place setup pipe before user supplied extra files, this is later restored by init
 	if fd, f, err := Setup(&p.cmd.ExtraFiles); err != nil {
-		return &StartError{true, "set up params stream", err, false, false}
+		return &StartError{
+			Fatal: true,
+			Step:  "set up params stream",
+			Err:   err,
+		}
 	} else {
 		p.setup = f
 		p.cmd.Env = []string{setupEnv + "=" + strconv.Itoa(fd)}
@@ -295,10 +310,16 @@ func (p *Container) Start() error {
 		runtime.LockOSThread()
 		p.wait = make(chan struct{})
 
-		done <- func() error { // setup depending on per-thread state must happen here
-			// PR_SET_NO_NEW_PRIVS: depends on per-thread state but acts on all processes created from that thread
+		// setup depending on per-thread state must happen here
+		done <- func() error {
+			// PR_SET_NO_NEW_PRIVS: thread-directed but acts on all processes
+			// created from the calling thread
 			if err := SetNoNewPrivs(); err != nil {
-				return &StartError{true, "prctl(PR_SET_NO_NEW_PRIVS)", err, false, false}
+				return &StartError{
+					Fatal: true,
+					Step:  "prctl(PR_SET_NO_NEW_PRIVS)",
+					Err:   err,
+				}
 			}
 
 			// landlock: depends on per-thread state but acts on a process group
@@ -310,28 +331,40 @@ func (p *Container) Start() error {
 
 				if abi, err := LandlockGetABI(); err != nil {
 					if p.HostAbstract {
-						// landlock can be skipped here as it restricts access to resources
-						// already covered by namespaces (pid)
+						// landlock can be skipped here as it restricts access
+						// to resources already covered by namespaces (pid)
 						goto landlockOut
 					}
-					return &StartError{false, "get landlock ABI", err, false, false}
+					return &StartError{Step: "get landlock ABI", Err: err}
 				} else if abi < 6 {
 					if p.HostAbstract {
 						// see above comment
 						goto landlockOut
 					}
-					return &StartError{false, "kernel version too old for LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET", ENOSYS, true, false}
+					return &StartError{
+						Step:   "kernel too old for LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET",
+						Err:    ENOSYS,
+						Origin: true,
+					}
 				} else {
 					p.msg.Verbosef("landlock abi version %d", abi)
 				}
 
 				if rulesetFd, err := rulesetAttr.Create(0); err != nil {
-					return &StartError{true, "create landlock ruleset", err, false, false}
+					return &StartError{
+						Fatal: true,
+						Step:  "create landlock ruleset",
+						Err:   err,
+					}
 				} else {
 					p.msg.Verbosef("enforcing landlock ruleset %s", rulesetAttr)
 					if err = LandlockRestrictSelf(rulesetFd, 0); err != nil {
 						_ = Close(rulesetFd)
-						return &StartError{true, "enforce landlock ruleset", err, false, false}
+						return &StartError{
+							Fatal: true,
+							Step:  "enforce landlock ruleset",
+							Err:   err,
+						}
 					}
 					if err = Close(rulesetFd); err != nil {
 						p.msg.Verbosef("cannot close landlock ruleset: %v", err)
@@ -342,9 +375,52 @@ func (p *Container) Start() error {
 			landlockOut:
 			}
 
+			// sched_setscheduler: thread-directed but acts on all processes
+			// created from the calling thread
+			if p.SetScheduler {
+				if p.SchedPolicy < 0 || p.SchedPolicy > std.SCHED_LAST {
+					return &StartError{
+						Fatal: false,
+						Step:  "set scheduling policy",
+						Err:   EINVAL,
+					}
+				}
+
+				var param schedParam
+				if priority, err := p.SchedPolicy.GetPriorityMin(); err != nil {
+					return &StartError{
+						Fatal: true,
+						Step:  "get minimum priority",
+						Err:   err,
+					}
+				} else {
+					param.priority = max(priority, p.SchedPriority)
+				}
+
+				p.msg.Verbosef(
+					"setting scheduling policy %s priority %d",
+					p.SchedPolicy, param.priority,
+				)
+				if err := schedSetscheduler(
+					0, // calling thread
+					p.SchedPolicy,
+					&param,
+				); err != nil {
+					return &StartError{
+						Fatal: true,
+						Step:  "set scheduling policy",
+						Err:   err,
+					}
+				}
+			}
+
 			p.msg.Verbose("starting container init")
 			if err := p.cmd.Start(); err != nil {
-				return &StartError{false, "start container init", err, false, true}
+				return &StartError{
+					Step:        "start container init",
+					Err:         err,
+					Passthrough: true,
+				}
 			}
 			return nil
 		}()
@@ -356,6 +432,7 @@ func (p *Container) Start() error {
 }
 
 // Serve serves [Container.Params] to the container init.
+//
 // Serve must only be called once.
 func (p *Container) Serve() error {
 	if p.setup == nil {
@@ -365,12 +442,21 @@ func (p *Container) Serve() error {
 	setup := p.setup
 	p.setup = nil
 	if err := setup.SetDeadline(time.Now().Add(initSetupTimeout)); err != nil {
-		return &StartError{true, "set init pipe deadline", err, false, true}
+		return &StartError{
+			Fatal:       true,
+			Step:        "set init pipe deadline",
+			Err:         err,
+			Passthrough: true,
+		}
 	}
 
 	if p.Path == nil {
 		p.cancel()
-		return &StartError{false, "invalid executable pathname", EINVAL, true, false}
+		return &StartError{
+			Step:   "invalid executable pathname",
+			Err:    EINVAL,
+			Origin: true,
+		}
 	}
 
 	// do not transmit nil
@@ -395,7 +481,8 @@ func (p *Container) Serve() error {
 	return err
 }
 
-// Wait waits for the container init process to exit and releases any resources associated with the [Container].
+// Wait blocks until the container init process to exit and releases any
+// resources associated with the [Container].
 func (p *Container) Wait() error {
 	if p.cmd == nil || p.cmd.Process == nil {
 		return EINVAL
@@ -440,11 +527,13 @@ func (p *Container) StderrPipe() (r io.ReadCloser, err error) {
 }
 
 func (p *Container) String() string {
-	return fmt.Sprintf("argv: %q, filter: %v, rules: %d, flags: %#x, presets: %#x",
-		p.Args, !p.SeccompDisable, len(p.SeccompRules), int(p.SeccompFlags), int(p.SeccompPresets))
+	return fmt.Sprintf(
+		"argv: %q, filter: %v, rules: %d, flags: %#x, presets: %#x",
+		p.Args, !p.SeccompDisable, len(p.SeccompRules), int(p.SeccompFlags), int(p.SeccompPresets),
+	)
 }
 
-// ProcessState returns the address to os.ProcessState held by the underlying [exec.Cmd].
+// ProcessState returns the address of os.ProcessState held by the underlying [exec.Cmd].
 func (p *Container) ProcessState() *os.ProcessState {
 	if p.cmd == nil {
 		return nil
@@ -452,7 +541,8 @@ func (p *Container) ProcessState() *os.ProcessState {
 	return p.cmd.ProcessState
 }
 
-// New returns the address to a new instance of [Container] that requires further initialisation before use.
+// New returns the address to a new instance of [Container]. This value requires
+// further initialisation before use.
 func New(ctx context.Context, msg message.Msg) *Container {
 	if msg == nil {
 		msg = message.New(nil)
@@ -461,12 +551,18 @@ func New(ctx context.Context, msg message.Msg) *Container {
 	p := &Container{ctx: ctx, msg: msg, Params: Params{Ops: new(Ops)}}
 	c, cancel := context.WithCancel(ctx)
 	p.cancel = cancel
-	p.cmd = exec.CommandContext(c, MustExecutable(msg))
+	p.cmd = exec.CommandContext(c, fhs.ProcSelfExe)
 	return p
 }
 
 // NewCommand calls [New] and initialises the [Params.Path] and [Params.Args] fields.
-func NewCommand(ctx context.Context, msg message.Msg, pathname *check.Absolute, name string, args ...string) *Container {
+func NewCommand(
+	ctx context.Context,
+	msg message.Msg,
+	pathname *check.Absolute,
+	name string,
+	args ...string,
+) *Container {
 	z := New(ctx, msg)
 	z.Path = pathname
 	z.Args = append([]string{name}, args...)

container/container_test.go

@@ -773,14 +773,13 @@ func TestMain(m *testing.M) {
 func helperNewContainerLibPaths(ctx context.Context, libPaths *[]*check.Absolute, args ...string) (c *container.Container) {
 	msg := message.New(nil)
 	msg.SwapVerbose(testing.Verbose())
-	executable := check.MustAbs(container.MustExecutable(msg))
 
 	c = container.NewCommand(ctx, msg, absHelperInnerPath, "helper", args...)
 	c.Env = append(c.Env, envDoCheck+"=1")
-	c.Bind(executable, absHelperInnerPath, 0)
+	c.Bind(fhs.AbsProcSelfExe, absHelperInnerPath, 0)
 
 	// in case test has cgo enabled
-	if entries, err := ldd.Resolve(ctx, msg, executable); err != nil {
+	if entries, err := ldd.Resolve(ctx, msg, nil); err != nil {
 		log.Fatalf("ldd: %v", err)
 	} else {
 		*libPaths = ldd.Path(entries)

container/dispatcher.go

@@ -21,7 +21,8 @@ type osFile interface {
 	fs.File
 }
 
-// syscallDispatcher provides methods that make state-dependent system calls as part of their behaviour.
+// syscallDispatcher provides methods that make state-dependent system calls as
+// part of their behaviour.
 type syscallDispatcher interface {
 	// new starts a goroutine with a new instance of syscallDispatcher.
 	// A syscallDispatcher must never be used in any goroutine other than the one owning it,

container/dispatcher_test.go

@@ -238,8 +238,11 @@ func sliceAddr[S any](s []S) *[]S { return &s }
 
 func newCheckedFile(t *testing.T, name, wantData string, closeErr error) osFile {
 	f := &checkedOsFile{t: t, name: name, want: wantData, closeErr: closeErr}
-	// check happens in Close, and cleanup is not guaranteed to run, so relying on it for sloppy implementations will cause sporadic test results
-	f.cleanup = runtime.AddCleanup(f, func(name string) { f.t.Fatalf("checkedOsFile %s became unreachable without a call to Close", name) }, f.name)
+	// check happens in Close, and cleanup is not guaranteed to run, so relying
+	// on it for sloppy implementations will cause sporadic test results
+	f.cleanup = runtime.AddCleanup(f, func(name string) {
+		panic("checkedOsFile " + name + " became unreachable without a call to Close")
+	}, name)
 	return f
 }
 

container/errors.go

@@ -43,7 +43,8 @@ func messageFromError(err error) (m string, ok bool) {
 }
 
 // messagePrefix checks and prefixes the error message of a non-pointer error.
-// While this is usable for pointer errors, such use should be avoided as nil check is omitted.
+// While this is usable for pointer errors, such use should be avoided as nil
+// check is omitted.
 func messagePrefix[T error](prefix string, err error) (string, bool) {
 	var targetError T
 	if errors.As(err, &targetError) {

container/executable.go

@@ -28,6 +28,9 @@ func copyExecutable(msg message.Msg) {
 	}
 }
 
+// MustExecutable calls [os.Executable] and terminates the process on error.
+//
+// Deprecated: This is no longer used and will be removed in 0.4.
 func MustExecutable(msg message.Msg) string {
 	executableOnce.Do(func() { copyExecutable(msg) })
 	return executable

container/fhs/abs.go

@@ -42,6 +42,8 @@ var (
 	AbsDevShm = unsafeAbs(DevShm)
 	// AbsProc is [Proc] as [check.Absolute].
 	AbsProc = unsafeAbs(Proc)
+	// AbsProcSelfExe is [ProcSelfExe] as [check.Absolute].
+	AbsProcSelfExe = unsafeAbs(ProcSelfExe)
 	// AbsSys is [Sys] as [check.Absolute].
 	AbsSys = unsafeAbs(Sys)
 )

container/fhs/fhs.go

@@ -9,7 +9,8 @@ const (
 	// Tmp points to the place for small temporary files.
 	Tmp = "/tmp/"
 
-	// Run points to a "tmpfs" file system for system packages to place runtime data, socket files, and similar.
+	// Run points to a "tmpfs" file system for system packages to place runtime
+	// data, socket files, and similar.
 	Run = "/run/"
 	// RunUser points to a directory containing per-user runtime directories,
 	// each usually individually mounted "tmpfs" instances.
@@ -17,10 +18,12 @@ const (
 
 	// Usr points to vendor-supplied operating system resources.
 	Usr = "/usr/"
-	// UsrBin points to binaries and executables for user commands that shall appear in the $PATH search path.
+	// UsrBin points to binaries and executables for user commands that shall
+	// appear in the $PATH search path.
 	UsrBin = Usr + "bin/"
 
-	// Var points to persistent, variable system data. Writable during normal system operation.
+	// Var points to persistent, variable system data. Writable during normal
+	// system operation.
 	Var = "/var/"
 	// VarLib points to persistent system data.
 	VarLib = Var + "lib/"
@@ -29,12 +32,20 @@ const (
 
 	// Dev points to the root directory for device nodes.
 	Dev = "/dev/"
-	// DevShm is the place for POSIX shared memory segments, as created via shm_open(3).
+	// DevShm is the place for POSIX shared memory segments, as created via
+	// shm_open(3).
 	DevShm = "/dev/shm/"
-	// Proc points to a virtual kernel file system exposing the process list and other functionality.
+	// Proc points to a virtual kernel file system exposing the process list and
+	// other functionality.
 	Proc = "/proc/"
-	// ProcSys points to a hierarchy below /proc/ that exposes a number of kernel tunables.
+	// ProcSys points to a hierarchy below /proc/ that exposes a number of
+	// kernel tunables.
 	ProcSys = Proc + "sys/"
-	// Sys points to a virtual kernel file system exposing discovered devices and other functionality.
+	// ProcSelf resolves to the process's own /proc/pid directory.
+	ProcSelf = Proc + "self/"
+	// ProcSelfExe is a symbolic link to program pathname.
+	ProcSelfExe = ProcSelf + "exe"
+	// Sys points to a virtual kernel file system exposing discovered devices
+	// and other functionality.
 	Sys = "/sys/"
 )

container/init.go

@@ -33,12 +33,12 @@ const (
 	- This path is only accessible by init and root:
 	  The container init sets SUID_DUMP_DISABLE and terminates if that fails.
 
-	It should be noted that none of this should become relevant at any point since the resulting
-	intermediate root tmpfs should be effectively anonymous. */
+	It should be noted that none of this should become relevant at any point
+	since the resulting intermediate root tmpfs should be effectively anonymous. */
 	intermediateHostPath = fhs.Proc + "self/fd"
 
-	// setupEnv is the name of the environment variable holding the string representation of
-	// the read end file descriptor of the setup params pipe.
+	// setupEnv is the name of the environment variable holding the string
+	// representation of the read end file descriptor of the setup params pipe.
 	setupEnv = "HAKUREI_SETUP"
 
 	// exitUnexpectedWait4 is the exit code if wait4 returns an unexpected errno.
@@ -59,7 +59,8 @@ type (
 		// late is called right before starting the initial process.
 		late(state *setupState, k syscallDispatcher) error
 
-		// prefix returns a log message prefix, and whether this Op prints no identifying message on its own.
+		// prefix returns a log message prefix, and whether this Op prints no
+		// identifying message on its own.
 		prefix() (string, bool)
 
 		Is(op Op) bool
@@ -71,9 +72,11 @@ type (
 	setupState struct {
 		nonrepeatable uintptr
 
-		// Whether early reaping has concluded. Must only be accessed in the wait4 loop.
+		// Whether early reaping has concluded. Must only be accessed in the
+		// wait4 loop.
 		processConcluded bool
-		// Process to syscall.WaitStatus populated in the wait4 loop. Freed after early reaping concludes.
+		// Process to syscall.WaitStatus populated in the wait4 loop. Freed
+		// after early reaping concludes.
 		process map[int]WaitStatus
 		// Synchronises access to process.
 		processMu sync.RWMutex
@@ -216,9 +219,10 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	defer cancel()
 
 	/* early is called right before pivot_root into intermediate root;
-	this step is mostly for gathering information that would otherwise be difficult to obtain
-	via library functions after pivot_root, and implementations are expected to avoid changing
-	the state of the mount namespace */
+	this step is mostly for gathering information that would otherwise be
+	difficult to obtain via library functions after pivot_root, and
+	implementations are expected to avoid changing the state of the mount
+	namespace */
 	for i, op := range *params.Ops {
 		if op == nil || !op.Valid() {
 			k.fatalf(msg, "invalid op at index %d", i)
@@ -258,10 +262,10 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		k.fatalf(msg, "cannot enter intermediate root: %v", err)
 	}
 
-	/* apply is called right after pivot_root and entering the new root;
-	this step sets up the container filesystem, and implementations are expected to keep the host root
-	and sysroot mount points intact but otherwise can do whatever they need to;
-	chdir is allowed but discouraged */
+	/* apply is called right after pivot_root and entering the new root. This
+	step sets up the container filesystem, and implementations are expected to
+	keep the host root and sysroot mount points intact but otherwise can do
+	whatever they need to. Calling chdir is allowed but discouraged. */
 	for i, op := range *params.Ops {
 		// ops already checked during early setup
 		if prefix, ok := op.prefix(); ok {

container/initbind.go

@@ -12,14 +12,16 @@ import (
 
 func init() { gob.Register(new(BindMountOp)) }
 
-// Bind appends an [Op] that bind mounts host path [BindMountOp.Source] on container path [BindMountOp.Target].
+// Bind is a helper for appending [BindMountOp] to [Ops].
 func (f *Ops) Bind(source, target *check.Absolute, flags int) *Ops {
 	*f = append(*f, &BindMountOp{nil, source, target, flags})
 	return f
 }
 
-// BindMountOp bind mounts host path Source on container path Target.
-// Note that Flags uses bits declared in this package and should not be set with constants in [syscall].
+// BindMountOp creates a bind mount from host path Source to container path Target.
+//
+// Note that Flags uses bits declared in the [std] package and should not be set
+// with constants in [syscall].
 type BindMountOp struct {
 	sourceFinal, Source, Target *check.Absolute
 

container/initdaemon.go

@@ -24,8 +24,7 @@ const (
 	daemonTimeout = 5 * time.Second
 )
 
-// Daemon appends an [Op] that starts a daemon in the container and blocks until
-// [DaemonOp.Target] appears.
+// Daemon is a helper for appending [DaemonOp] to [Ops].
 func (f *Ops) Daemon(target, path *check.Absolute, args ...string) *Ops {
 	*f = append(*f, &DaemonOp{target, path, args})
 	return f

container/initdev.go

@@ -19,7 +19,9 @@ func (f *Ops) Dev(target *check.Absolute, mqueue bool) *Ops {
 }
 
 // DevWritable appends an [Op] that mounts a writable subset of host /dev.
-// There is usually no good reason to write to /dev, so this should always be followed by a [RemountOp].
+//
+// There is usually no good reason to write to /dev, so this should always be
+// followed by a [RemountOp].
 func (f *Ops) DevWritable(target *check.Absolute, mqueue bool) *Ops {
 	*f = append(*f, &MountDevOp{target, mqueue, true})
 	return f

container/initmkdir.go

@@ -10,7 +10,7 @@ import (
 
 func init() { gob.Register(new(MkdirOp)) }
 
-// Mkdir appends an [Op] that creates a directory in the container filesystem.
+// Mkdir is a helper for appending [MkdirOp] to [Ops].
 func (f *Ops) Mkdir(name *check.Absolute, perm os.FileMode) *Ops {
 	*f = append(*f, &MkdirOp{name, perm})
 	return f

container/initoverlay.go

@@ -54,8 +54,11 @@ func (e *OverlayArgumentError) Error() string {
 	}
 }
 
-// Overlay appends an [Op] that mounts the overlay pseudo filesystem on [MountOverlayOp.Target].
-func (f *Ops) Overlay(target, state, work *check.Absolute, layers ...*check.Absolute) *Ops {
+// Overlay is a helper for appending [MountOverlayOp] to [Ops].
+func (f *Ops) Overlay(
+	target, state, work *check.Absolute,
+	layers ...*check.Absolute,
+) *Ops {
 	*f = append(*f, &MountOverlayOp{
 		Target: target,
 		Lower:  layers,
@@ -65,13 +68,12 @@ func (f *Ops) Overlay(target, state, work *check.Absolute, layers ...*check.Abso
 	return f
 }
 
-// OverlayEphemeral appends an [Op] that mounts the overlay pseudo filesystem on [MountOverlayOp.Target]
-// with an ephemeral upperdir and workdir.
+// OverlayEphemeral appends a [MountOverlayOp] with an ephemeral upperdir and workdir.
 func (f *Ops) OverlayEphemeral(target *check.Absolute, layers ...*check.Absolute) *Ops {
 	return f.Overlay(target, fhs.AbsRoot, nil, layers...)
 }
 
-// OverlayReadonly appends an [Op] that mounts the overlay pseudo filesystem readonly on [MountOverlayOp.Target]
+// OverlayReadonly appends a readonly [MountOverlayOp].
 func (f *Ops) OverlayReadonly(target *check.Absolute, layers ...*check.Absolute) *Ops {
 	return f.Overlay(target, nil, nil, layers...)
 }
@@ -82,25 +84,34 @@ type MountOverlayOp struct {
 
 	// Any filesystem, does not need to be on a writable filesystem.
 	Lower []*check.Absolute
-	// formatted for [OptionOverlayLowerdir], resolved, prefixed and escaped during early
+	// Formatted for [OptionOverlayLowerdir].
+	//
+	// Resolved, prefixed and escaped during early.
 	lower []string
+
 	// The upperdir is normally on a writable filesystem.
 	//
-	// If Work is nil and Upper holds the special value [fhs.AbsRoot],
-	// an ephemeral upperdir and workdir will be set up.
+	// If Work is nil and Upper holds the special value [fhs.AbsRoot], an
+	// ephemeral upperdir and workdir will be set up.
 	//
-	// If both Work and Upper are nil, upperdir and workdir is omitted and the overlay is mounted readonly.
+	// If both Work and Upper are nil, upperdir and workdir is omitted and the
+	// overlay is mounted readonly.
 	Upper *check.Absolute
-	// formatted for [OptionOverlayUpperdir], resolved, prefixed and escaped during early
+	// Formatted for [OptionOverlayUpperdir].
+	//
+	// Resolved, prefixed and escaped during early.
 	upper string
+
 	// The workdir needs to be an empty directory on the same filesystem as upperdir.
 	Work *check.Absolute
-	// formatted for [OptionOverlayWorkdir], resolved, prefixed and escaped during early
+	// Formatted for [OptionOverlayWorkdir].
+	//
+	// Resolved, prefixed and escaped during early.
 	work string
 
 	ephemeral bool
 
-	// used internally for mounting to the intermediate root
+	// Used internally for mounting to the intermediate root.
 	noPrefix bool
 }
 

container/initplace.go

@@ -16,7 +16,7 @@ const (
 
 func init() { gob.Register(new(TmpfileOp)) }
 
-// Place appends an [Op] that places a file in container path [TmpfileOp.Path] containing [TmpfileOp.Data].
+// Place is a helper for appending [TmpfileOp] to [Ops].
 func (f *Ops) Place(name *check.Absolute, data []byte) *Ops {
 	*f = append(*f, &TmpfileOp{name, data})
 	return f

container/initplace_test.go

@@ -21,7 +21,7 @@ func TestTmpfileOp(t *testing.T) {
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []stub.Call{
-			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), stub.UniqueError(5)),
+			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, (*checkedOsFile)(nil), stub.UniqueError(5)),
 		}, stub.UniqueError(5)},
 
 		{"Write", &Params{ParentPerm: 0700}, &TmpfileOp{
@@ -35,14 +35,14 @@ func TestTmpfileOp(t *testing.T) {
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []stub.Call{
-			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, stub.UniqueError(3)), nil),
+			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.Close", sampleDataString, stub.UniqueError(3)), nil),
 		}, stub.UniqueError(3)},
 
 		{"ensureFile", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []stub.Call{
-			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil),
+			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.ensureFile", sampleDataString, nil), nil),
 			call("ensureFile", stub.ExpectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, stub.UniqueError(2)),
 		}, stub.UniqueError(2)},
 
@@ -50,29 +50,29 @@ func TestTmpfileOp(t *testing.T) {
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []stub.Call{
-			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil),
+			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.bindMount", sampleDataString, nil), nil),
 			call("ensureFile", stub.ExpectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil),
-			call("bindMount", stub.ExpectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, stub.UniqueError(1)),
+			call("bindMount", stub.ExpectArgs{"tmp.bindMount", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, stub.UniqueError(1)),
 		}, stub.UniqueError(1)},
 
 		{"remove", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []stub.Call{
-			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil),
+			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.remove", sampleDataString, nil), nil),
 			call("ensureFile", stub.ExpectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil),
-			call("bindMount", stub.ExpectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil),
-			call("remove", stub.ExpectArgs{"tmp.32768"}, nil, stub.UniqueError(0)),
+			call("bindMount", stub.ExpectArgs{"tmp.remove", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil),
+			call("remove", stub.ExpectArgs{"tmp.remove"}, nil, stub.UniqueError(0)),
 		}, stub.UniqueError(0)},
 
 		{"success", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []stub.Call{
-			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil),
+			call("createTemp", stub.ExpectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.success", sampleDataString, nil), nil),
 			call("ensureFile", stub.ExpectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil),
-			call("bindMount", stub.ExpectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil),
-			call("remove", stub.ExpectArgs{"tmp.32768"}, nil, nil),
+			call("bindMount", stub.ExpectArgs{"tmp.success", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil),
+			call("remove", stub.ExpectArgs{"tmp.success"}, nil, nil),
 		}, nil},
 	})
 

container/initproc.go

@@ -10,7 +10,7 @@ import (
 
 func init() { gob.Register(new(MountProcOp)) }
 
-// Proc appends an [Op] that mounts a private instance of proc.
+// Proc is a helper for appending [MountProcOp] to [Ops].
 func (f *Ops) Proc(target *check.Absolute) *Ops {
 	*f = append(*f, &MountProcOp{target})
 	return f

container/initremount.go

@@ -9,7 +9,7 @@ import (
 
 func init() { gob.Register(new(RemountOp)) }
 
-// Remount appends an [Op] that applies [RemountOp.Flags] on container path [RemountOp.Target].
+// Remount is a helper for appending [RemountOp] to [Ops].
 func (f *Ops) Remount(target *check.Absolute, flags uintptr) *Ops {
 	*f = append(*f, &RemountOp{target, flags})
 	return f

container/landlock.go

@@ -38,6 +38,7 @@ const (
 	_LANDLOCK_ACCESS_FS_DELIM
 )
 
+// String returns a space-separated string of [LandlockAccessFS] flags.
 func (f LandlockAccessFS) String() string {
 	switch f {
 	case LANDLOCK_ACCESS_FS_EXECUTE:
@@ -116,6 +117,7 @@ const (
 	_LANDLOCK_ACCESS_NET_DELIM
 )
 
+// String returns a space-separated string of [LandlockAccessNet] flags.
 func (f LandlockAccessNet) String() string {
 	switch f {
 	case LANDLOCK_ACCESS_NET_BIND_TCP:
@@ -152,6 +154,7 @@ const (
 	_LANDLOCK_SCOPE_DELIM
 )
 
+// String returns a space-separated string of [LandlockScope] flags.
 func (f LandlockScope) String() string {
 	switch f {
 	case LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET:
@@ -184,10 +187,12 @@ type RulesetAttr struct {
 	HandledAccessFS LandlockAccessFS
 	// Bitmask of handled network actions.
 	HandledAccessNet LandlockAccessNet
-	// Bitmask of scopes restricting a Landlock domain from accessing outside resources (e.g. IPCs).
+	// Bitmask of scopes restricting a Landlock domain from accessing outside
+	// resources (e.g. IPCs).
 	Scoped LandlockScope
 }
 
+// String returns a user-facing description of [RulesetAttr].
 func (rulesetAttr *RulesetAttr) String() string {
 	if rulesetAttr == nil {
 		return "NULL"
@@ -208,6 +213,7 @@ func (rulesetAttr *RulesetAttr) String() string {
 	return strings.Join(elems, ", ")
 }
 
+// Create loads the ruleset into the kernel.
 func (rulesetAttr *RulesetAttr) Create(flags uintptr) (fd int, err error) {
 	var pointer, size uintptr
 	// NULL needed for abi version
@@ -216,10 +222,13 @@ func (rulesetAttr *RulesetAttr) Create(flags uintptr) (fd int, err error) {
 		size = unsafe.Sizeof(*rulesetAttr)
 	}
 
-	rulesetFd, _, errno := syscall.Syscall(std.SYS_LANDLOCK_CREATE_RULESET, pointer, size, flags)
+	rulesetFd, _, errno := syscall.Syscall(
+		std.SYS_LANDLOCK_CREATE_RULESET,
+		pointer, size,
+		flags,
+	)
 	fd = int(rulesetFd)
 	err = errno
-
 	if fd < 0 {
 		return
 	}
@@ -230,12 +239,19 @@ func (rulesetAttr *RulesetAttr) Create(flags uintptr) (fd int, err error) {
 	return fd, nil
 }
 
+// LandlockGetABI returns the ABI version supported by the kernel.
 func LandlockGetABI() (int, error) {
 	return (*RulesetAttr)(nil).Create(LANDLOCK_CREATE_RULESET_VERSION)
 }
 
+// LandlockRestrictSelf applies a loaded ruleset to the calling thread.
 func LandlockRestrictSelf(rulesetFd int, flags uintptr) error {
-	r, _, errno := syscall.Syscall(std.SYS_LANDLOCK_RESTRICT_SELF, uintptr(rulesetFd), flags, 0)
+	r, _, errno := syscall.Syscall(
+		std.SYS_LANDLOCK_RESTRICT_SELF,
+		uintptr(rulesetFd),
+		flags,
+		0,
+	)
 	if r != 0 {
 		return errno
 	}

container/netlink.go

@@ -99,7 +99,7 @@ done:
 				}
 				if m.Header.Type == NLMSG_ERROR {
 					if len(m.Data) >= 4 {
-						errno := Errno(-std.ScmpInt(binary.NativeEndian.Uint32(m.Data)))
+						errno := Errno(-std.Int(binary.NativeEndian.Uint32(m.Data)))
 						if errno == 0 {
 							return nil
 						}

container/path.go

@@ -15,7 +15,10 @@ import (
 
 const (
 	// Nonexistent is a path that cannot exist.
-	// /proc is chosen because a system with covered /proc is unsupported by this package.
+	//
+	// This path can never be presented by the kernel if proc is mounted on
+	// /proc/. This can only exist if parts of /proc/ is covered, or proc is not
+	// mounted at all. Neither configuration is supported by this package.
 	Nonexistent = fhs.Proc + "nonexistent"
 
 	hostPath    = fhs.Root + hostDir

container/seccomp/libseccomp.go

@@ -88,18 +88,22 @@ var resPrefix = [...]string{
 	7: "seccomp_load failed",
 }
 
-// cbAllocateBuffer is the function signature for the function handle passed to hakurei_export_filter
-// which allocates the buffer that the resulting bpf program is copied into, and writes its slice header
-// to a value held by the caller.
+// cbAllocateBuffer is the function signature for the function handle passed to
+// hakurei_scmp_make_filter which allocates the buffer that the resulting bpf
+// program is copied into, and writes its slice header to a value held by the caller.
 type cbAllocateBuffer = func(len C.size_t) (buf unsafe.Pointer)
 
+// hakurei_scmp_allocate allocates a buffer of specified size known to the
+// runtime through a callback passed in a [cgo.Handle].
+//
 //export hakurei_scmp_allocate
 func hakurei_scmp_allocate(f C.uintptr_t, len C.size_t) (buf unsafe.Pointer) {
 	return cgo.Handle(f).Value().(cbAllocateBuffer)(len)
 }
 
-// makeFilter generates a bpf program from a slice of [std.NativeRule] and writes the resulting byte slice to p.
-// The filter is installed to the current process if p is nil.
+// makeFilter generates a bpf program from a slice of [std.NativeRule] and
+// writes the resulting byte slice to p. The filter is installed to the current
+// process if p is nil.
 func makeFilter(rules []std.NativeRule, flags ExportFlag, p *[]byte) error {
 	if len(rules) == 0 {
 		return ErrInvalidRules
@@ -170,8 +174,8 @@ func Export(rules []std.NativeRule, flags ExportFlag) (data []byte, err error) {
 	return
 }
 
-// Load generates a bpf program from a slice of [std.NativeRule] and enforces it on the current process.
-// Errors returned by libseccomp is wrapped in [LibraryError].
+// Load generates a bpf program from a slice of [std.NativeRule] and enforces it
+// on the current process. Errors returned by libseccomp is wrapped in [LibraryError].
 func Load(rules []std.NativeRule, flags ExportFlag) error { return makeFilter(rules, flags, nil) }
 
 type (

container/seccomp/std_test.go

@@ -24,8 +24,8 @@ func TestSyscallResolveName(t *testing.T) {
 }
 
 func TestRuleType(t *testing.T) {
-	assertKind[std.ScmpUint, scmpUint](t)
-	assertKind[std.ScmpInt, scmpInt](t)
+	assertKind[std.Uint, scmpUint](t)
+	assertKind[std.Int, scmpInt](t)
 
 	assertSize[std.NativeRule, syscallRule](t)
 	assertKind[std.ScmpDatum, scmpDatum](t)

container/std/seccomp.go

@@ -7,24 +7,28 @@ import (
 
 type (
 	// ScmpUint is equivalent to C.uint.
-	ScmpUint uint32
+	//
+	// Deprecated: This type has been renamed to Uint and will be removed in 0.4.
+	ScmpUint = Uint
 	// ScmpInt is equivalent to C.int.
-	ScmpInt int32
+	//
+	// Deprecated: This type has been renamed to Int and will be removed in 0.4.
+	ScmpInt = Int
 
 	// ScmpSyscall represents a syscall number passed to libseccomp via [NativeRule.Syscall].
-	ScmpSyscall ScmpInt
+	ScmpSyscall Int
 	// ScmpErrno represents an errno value passed to libseccomp via [NativeRule.Errno].
-	ScmpErrno ScmpInt
+	ScmpErrno Int
 
 	// ScmpCompare is equivalent to enum scmp_compare;
-	ScmpCompare ScmpUint
+	ScmpCompare Uint
 	// ScmpDatum is equivalent to scmp_datum_t.
 	ScmpDatum uint64
 
 	// ScmpArgCmp is equivalent to struct scmp_arg_cmp.
 	ScmpArgCmp struct {
 		// argument number, starting at 0
-		Arg ScmpUint `json:"arg"`
+		Arg Uint `json:"arg"`
 		// the comparison op, e.g. SCMP_CMP_*
 		Op ScmpCompare `json:"op"`
 

container/std/syscall.go

@@ -1,6 +1,12 @@
 package std
 
-import "iter"
+import (
+	"encoding"
+	"iter"
+	"strconv"
+	"sync"
+	"syscall"
+)
 
 // Syscalls returns an iterator over all wired syscalls.
 func Syscalls() iter.Seq2[string, ScmpSyscall] {
@@ -26,3 +32,128 @@ func SyscallResolveName(name string) (num ScmpSyscall, ok bool) {
 	num, ok = syscallNumExtra[name]
 	return
 }
+
+// SchedPolicy denotes a scheduling policy defined in include/uapi/linux/sched.h.
+type SchedPolicy int
+
+// include/uapi/linux/sched.h
+const (
+	SCHED_NORMAL SchedPolicy = iota
+	SCHED_FIFO
+	SCHED_RR
+	SCHED_BATCH
+	_SCHED_ISO // SCHED_ISO: reserved but not implemented yet
+	SCHED_IDLE
+	SCHED_DEADLINE
+	SCHED_EXT
+
+	SCHED_LAST SchedPolicy = iota - 1
+)
+
+var _ encoding.TextMarshaler = SCHED_LAST
+var _ encoding.TextUnmarshaler = new(SCHED_LAST)
+
+// String returns a unique representation of policy, also used in encoding.
+func (policy SchedPolicy) String() string {
+	switch policy {
+	case SCHED_NORMAL:
+		return ""
+	case SCHED_FIFO:
+		return "fifo"
+	case SCHED_RR:
+		return "rr"
+	case SCHED_BATCH:
+		return "batch"
+	case SCHED_IDLE:
+		return "idle"
+	case SCHED_DEADLINE:
+		return "deadline"
+	case SCHED_EXT:
+		return "ext"
+
+	default:
+		return "invalid policy " + strconv.Itoa(int(policy))
+	}
+}
+
+// MarshalText performs bounds checking and returns the result of String.
+func (policy SchedPolicy) MarshalText() ([]byte, error) {
+	if policy == _SCHED_ISO || policy < 0 || policy > SCHED_LAST {
+		return nil, syscall.EINVAL
+	}
+	return []byte(policy.String()), nil
+}
+
+// InvalidSchedPolicyError is an invalid string representation of a [SchedPolicy].
+type InvalidSchedPolicyError string
+
+func (InvalidSchedPolicyError) Unwrap() error { return syscall.EINVAL }
+func (e InvalidSchedPolicyError) Error() string {
+	return "invalid scheduling policy " + strconv.Quote(string(e))
+}
+
+// UnmarshalText is the inverse of MarshalText.
+func (policy *SchedPolicy) UnmarshalText(text []byte) error {
+	switch string(text) {
+	case "fifo":
+		*policy = SCHED_FIFO
+	case "rr":
+		*policy = SCHED_RR
+	case "batch":
+		*policy = SCHED_BATCH
+	case "idle":
+		*policy = SCHED_IDLE
+	case "deadline":
+		*policy = SCHED_DEADLINE
+	case "ext":
+		*policy = SCHED_EXT
+
+	case "":
+		*policy = 0
+		return nil
+	default:
+		return InvalidSchedPolicyError(text)
+	}
+	return nil
+}
+
+// for sched_get_priority_max and sched_get_priority_min
+var (
+	schedPriority     [SCHED_LAST + 1][2]Int
+	schedPriorityErr  [SCHED_LAST + 1][2]error
+	schedPriorityOnce [SCHED_LAST + 1][2]sync.Once
+)
+
+// GetPriorityMax returns the maximum priority value that can be used with the
+// scheduling algorithm identified by policy.
+func (policy SchedPolicy) GetPriorityMax() (Int, error) {
+	schedPriorityOnce[policy][0].Do(func() {
+		priority, _, errno := syscall.Syscall(
+			syscall.SYS_SCHED_GET_PRIORITY_MAX,
+			uintptr(policy),
+			0, 0,
+		)
+		schedPriority[policy][0] = Int(priority)
+		if errno != 0 {
+			schedPriorityErr[policy][0] = errno
+		}
+	})
+	return schedPriority[policy][0], schedPriorityErr[policy][0]
+}
+
+// GetPriorityMin returns the minimum priority value that can be used with the
+// scheduling algorithm identified by policy.
+func (policy SchedPolicy) GetPriorityMin() (Int, error) {
+	schedPriorityOnce[policy][1].Do(func() {
+		priority, _, errno := syscall.Syscall(
+			syscall.SYS_SCHED_GET_PRIORITY_MIN,
+			uintptr(policy),
+			0, 0,
+		)
+		schedPriority[policy][1] = Int(priority)
+		if errno != 0 {
+			schedPriorityErr[policy][1] = errno
+		}
+	})
+	return schedPriority[policy][1], schedPriorityErr[policy][1]
+}

container/std/syscall_test.go

@@ -1,6 +1,11 @@
 package std_test
 
 import (
+	"encoding/json"
+	"errors"
+	"math"
+	"reflect"
+	"syscall"
 	"testing"
 
 	"hakurei.app/container/std"
@@ -19,3 +24,90 @@ func TestSyscallResolveName(t *testing.T) {
 		})
 	}
 }
+
+func TestSchedPolicyJSON(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		policy    std.SchedPolicy
+		want      string
+		encodeErr error
+		decodeErr error
+	}{
+		{std.SCHED_NORMAL, `""`, nil, nil},
+		{std.SCHED_FIFO, `"fifo"`, nil, nil},
+		{std.SCHED_RR, `"rr"`, nil, nil},
+		{std.SCHED_BATCH, `"batch"`, nil, nil},
+		{4, `"invalid policy 4"`, syscall.EINVAL, std.InvalidSchedPolicyError("invalid policy 4")},
+		{std.SCHED_IDLE, `"idle"`, nil, nil},
+		{std.SCHED_DEADLINE, `"deadline"`, nil, nil},
+		{std.SCHED_EXT, `"ext"`, nil, nil},
+		{math.MaxInt, `"iso"`, syscall.EINVAL, std.InvalidSchedPolicyError("iso")},
+	}
+	for _, tc := range testCases {
+		name := tc.policy.String()
+		if tc.policy == std.SCHED_NORMAL {
+			name = "normal"
+		}
+
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			got, err := json.Marshal(tc.policy)
+			if !errors.Is(err, tc.encodeErr) {
+				t.Fatalf("Marshal: error = %v, want %v", err, tc.encodeErr)
+			}
+			if err == nil && string(got) != tc.want {
+				t.Fatalf("Marshal: %s, want %s", string(got), tc.want)
+			}
+
+			var v std.SchedPolicy
+			if err = json.Unmarshal([]byte(tc.want), &v); !reflect.DeepEqual(err, tc.decodeErr) {
+				t.Fatalf("Unmarshal: error = %v, want %v", err, tc.decodeErr)
+			}
+			if err == nil && v != tc.policy {
+				t.Fatalf("Unmarshal: %d, want %d", v, tc.policy)
+			}
+		})
+	}
+}
+
+func TestSchedPolicyMinMax(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		policy   std.SchedPolicy
+		min, max std.Int
+		err      error
+	}{
+		{std.SCHED_NORMAL, 0, 0, nil},
+		{std.SCHED_FIFO, 1, 99, nil},
+		{std.SCHED_RR, 1, 99, nil},
+		{std.SCHED_BATCH, 0, 0, nil},
+		{4, -1, -1, syscall.EINVAL},
+		{std.SCHED_IDLE, 0, 0, nil},
+		{std.SCHED_DEADLINE, 0, 0, nil},
+		{std.SCHED_EXT, 0, 0, nil},
+	}
+	for _, tc := range testCases {
+		name := tc.policy.String()
+		if tc.policy == std.SCHED_NORMAL {
+			name = "normal"
+		}
+
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			if priority, err := tc.policy.GetPriorityMax(); !reflect.DeepEqual(err, tc.err) {
+				t.Fatalf("GetPriorityMax: error = %v, want %v", err, tc.err)
+			} else if priority != tc.max {
+				t.Fatalf("GetPriorityMax: %d, want %d", priority, tc.max)
+			}
+			if priority, err := tc.policy.GetPriorityMin(); !reflect.DeepEqual(err, tc.err) {
+				t.Fatalf("GetPriorityMin: error = %v, want %v", err, tc.err)
+			} else if priority != tc.min {
+				t.Fatalf("GetPriorityMin: %d, want %d", priority, tc.min)
+			}
+		})
+	}
+}

container/std/types.go

@@ -0,0 +1,8 @@
+package std
+
+type (
+	// Uint is equivalent to C.uint.
+	Uint uint32
+	// Int is equivalent to C.int.
+	Int int32
+)

container/syscall.go

@@ -3,6 +3,8 @@ package container
 import (
 	. "syscall"
 	"unsafe"
+
+	"hakurei.app/container/std"
 )
 
 // Prctl manipulates various aspects of the behavior of the calling thread or process.
@@ -41,6 +43,37 @@ func Isatty(fd int) bool {
 	return r == 0
 }
 
+// schedParam is equivalent to struct sched_param from include/linux/sched.h.
+type schedParam struct {
+	// sched_priority
+	priority std.Int
+}
+
+// schedSetscheduler sets both the scheduling policy and parameters for the
+// thread whose ID is specified in tid. If tid equals zero, the scheduling
+// policy and parameters of the calling thread will be set.
+//
+// This function is unexported because it is [very subtle to use correctly]. The
+// function signature in libc is misleading: pid actually refers to a thread ID.
+// The glibc wrapper for this system call ignores this semantic and exposes
+// this counterintuitive behaviour.
+//
+// This function is only called from the container setup thread. Do not reuse
+// this if you do not have something similar in place!
+//
+// [very subtle to use correctly]: https://www.openwall.com/lists/musl/2016/03/01/4
+func schedSetscheduler(tid int, policy std.SchedPolicy, param *schedParam) error {
+	if _, _, errno := Syscall(
+		SYS_SCHED_SETSCHEDULER,
+		uintptr(tid),
+		uintptr(policy),
+		uintptr(unsafe.Pointer(param)),
+	); errno != 0 {
+		return errno
+	}
+	return nil
+}
+
 // IgnoringEINTR makes a function call and repeats it if it returns an
 // EINTR error. This appears to be required even though we install all
 // signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.

container/vfs/mangle.go

@@ -2,6 +2,8 @@ package vfs
 
 import "strings"
 
+// Unmangle reverses mangling of strings done by the kernel. Its behaviour is
+// consistent with the equivalent function in util-linux.
 func Unmangle(s string) string {
 	if !strings.ContainsRune(s, '\\') {
 		return s

container/vfs/mountinfo.go

@@ -24,6 +24,7 @@ var (
 	ErrMountInfoSep    = errors.New("bad optional fields separator")
 )
 
+// A DecoderError describes a nonrecoverable error decoding a mountinfo stream.
 type DecoderError struct {
 	Op   string
 	Line int
@@ -51,7 +52,8 @@ func (e *DecoderError) Error() string {
 }
 
 type (
-	// A MountInfoDecoder reads and decodes proc_pid_mountinfo(5) entries from an input stream.
+	// A MountInfoDecoder reads and decodes proc_pid_mountinfo(5) entries from
+	// an input stream.
 	MountInfoDecoder struct {
 		s *bufio.Scanner
 		m *MountInfo
@@ -72,13 +74,16 @@ type (
 	MountInfoEntry struct {
 		// mount ID: a unique ID for the mount (may be reused after umount(2)).
 		ID int `json:"id"`
-		// parent ID: the ID of the parent mount (or of self for the root of this mount namespace's mount tree).
+		// parent ID: the ID of the parent mount (or of self for the root of
+		// this mount namespace's mount tree).
 		Parent int `json:"parent"`
 		// major:minor: the value of st_dev for files on this filesystem (see stat(2)).
 		Devno DevT `json:"devno"`
-		// root: the pathname of the directory in the filesystem which forms the root of this mount.
+		// root: the pathname of the directory in the filesystem which forms the
+		// root of this mount.
 		Root string `json:"root"`
-		// mount point: the pathname of the mount point relative to the process's root directory.
+		// mount point: the pathname of the mount point relative to the
+		// process's root directory.
 		Target string `json:"target"`
 		// mount options: per-mount options (see mount(2)).
 		VfsOptstr string `json:"vfs_optstr"`
@@ -126,7 +131,8 @@ func (e *MountInfoEntry) Flags() (flags uintptr, unmatched []string) {
 
 // NewMountInfoDecoder returns a new decoder that reads from r.
 //
-// The decoder introduces its own buffering and may read data from r beyond the mountinfo entries requested.
+// The decoder introduces its own buffering and may read data from r beyond the
+// mountinfo entries requested.
 func NewMountInfoDecoder(r io.Reader) *MountInfoDecoder {
 	return &MountInfoDecoder{s: bufio.NewScanner(r)}
 }
@@ -271,6 +277,8 @@ func parseMountInfoLine(s string, ent *MountInfoEntry) error {
 	return nil
 }
 
+// EqualWithIgnore compares to [MountInfoEntry] values, ignoring fields that
+// compare equal to ignore.
 func (e *MountInfoEntry) EqualWithIgnore(want *MountInfoEntry, ignore string) bool {
 	return (e.ID == want.ID || want.ID == -1) &&
 		(e.Parent == want.Parent || want.Parent == -1) &&
@@ -284,6 +292,8 @@ func (e *MountInfoEntry) EqualWithIgnore(want *MountInfoEntry, ignore string) bo
 		(e.FsOptstr == want.FsOptstr || want.FsOptstr == ignore)
 }
 
+// String returns a user-facing representation of a [MountInfoEntry]. It fits
+// roughly into the mountinfo format, but without mangling.
 func (e *MountInfoEntry) String() string {
 	return fmt.Sprintf("%d %d %d:%d %s %s %s %s %s %s %s",
 		e.ID, e.Parent, e.Devno[0], e.Devno[1], e.Root, e.Target, e.VfsOptstr,

container/vfs/unfold.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 )
 
+// UnfoldTargetError is a pathname that never appeared in a mount hierarchy.
 type UnfoldTargetError string
 
 func (e UnfoldTargetError) Error() string {
@@ -27,6 +28,7 @@ func (n *MountInfoNode) Collective() iter.Seq[*MountInfoNode] {
 	return func(yield func(*MountInfoNode) bool) { n.visit(yield) }
 }
 
+// visit recursively visits all visible mountinfo nodes.
 func (n *MountInfoNode) visit(yield func(*MountInfoNode) bool) bool {
 	if !n.Covered && !yield(n) {
 		return false

dist/release.sh

@@ -13,7 +13,7 @@ echo
 echo '# Building hakurei.'
 go generate ./...
 go build -trimpath -v -o "${out}/bin/" -ldflags "-s -w
-  -buildid= -extldflags '-static'
+  -buildid= -linkmode external -extldflags=-static
   -X hakurei.app/internal/info.buildVersion=${VERSION}
   -X hakurei.app/internal/info.hakureiPath=/usr/bin/hakurei
   -X hakurei.app/internal/info.hsuPath=/usr/bin/hsu
@@ -21,7 +21,7 @@ go build -trimpath -v -o "${out}/bin/" -ldflags "-s -w
 echo
 
 echo '# Testing hakurei.'
-go test -ldflags='-buildid= -extldflags=-static' ./...
+go test -ldflags='-buildid= -linkmode external -extldflags=-static' ./...
 echo
 
 echo '# Creating distribution.'

flake.lock

@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1765384171,
-        "narHash": "sha256-FuFtkJrW1Z7u+3lhzPRau69E0CNjADku1mLQQflUORo=",
+        "lastModified": 1772985280,
+        "narHash": "sha256-FdrNykOoY9VStevU4zjSUdvsL9SzJTcXt4omdEDZDLk=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "44777152652bc9eacf8876976fa72cc77ca8b9d8",
+        "rev": "8f736f007139d7f70752657dff6a401a585d6cbc",
         "type": "github"
       },
       "original": {
@@ -23,11 +23,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1765311797,
-        "narHash": "sha256-mSD5Ob7a+T2RNjvPvOA1dkJHGVrNVl8ZOrAwBjKBDQo=",
+        "lastModified": 1772822230,
+        "narHash": "sha256-yf3iYLGbGVlIthlQIk5/4/EQDZNNEmuqKZkQssMljuw=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "09eb77e94fa25202af8f3e81ddc7353d9970ac1b",
+        "rev": "71caefce12ba78d84fe618cf61644dce01cf3a96",
         "type": "github"
       },
       "original": {

flake.nix

@@ -29,20 +29,6 @@
     {
       nixosModules.hakurei = import ./nixos.nix self.packages;
 
-      buildPackage = forAllSystems (
-        system:
-        nixpkgsFor.${system}.callPackage (
-          import ./cmd/hpkg/build.nix {
-            inherit
-              nixpkgsFor
-              system
-              nixpkgs
-              home-manager
-              ;
-          }
-        )
-      );
-
       checks = forAllSystems (
         system:
         let
@@ -71,8 +57,6 @@
 
           sharefs = callPackage ./cmd/sharefs/test { inherit system self; };
 
-          hpkg = callPackage ./cmd/hpkg/test { inherit system self; };
-
           formatting = runCommandLocal "check-formatting" { nativeBuildInputs = [ nixfmt-rfc-style ]; } ''
             cd ${./.}
 
@@ -115,7 +99,7 @@
           hakurei = pkgs.pkgsStatic.callPackage ./package.nix {
             inherit (pkgs)
               # passthru.buildInputs
-              go
+              go_1_26
               clang
 
               # nativeBuildInputs
@@ -127,11 +111,6 @@
               glibc
               xdg-dbus-proxy
 
-              # hpkg
-              zstd
-              gnutar
-              coreutils
-
               # for check
               util-linux
               nettools
@@ -203,7 +182,7 @@
                         let
                           # this is used for interactive vm testing during development, where tests might be broken
                           package = self.packages.${pkgs.stdenv.hostPlatform.system}.hakurei.override {
-                            buildGoModule = previousArgs: pkgs.pkgsStatic.buildGoModule (previousArgs // { doCheck = false; });
+                            buildGo126Module = previousArgs: pkgs.pkgsStatic.buildGo126Module (previousArgs // { doCheck = false; });
                           };
                         in
                         {
@@ -219,7 +198,7 @@
                   ./test/interactive/trace.nix
 
                   self.nixosModules.hakurei
-                  self.inputs.home-manager.nixosModules.home-manager
+                  home-manager.nixosModules.home-manager
                 ];
               };
             in

go.mod

@@ -1,3 +1,3 @@
 module hakurei.app
 
-go 1.25
+go 1.26

hst/config.go

@@ -6,96 +6,137 @@ import (
 	"strings"
 
 	"hakurei.app/container/check"
+	"hakurei.app/container/std"
 )
 
-// Config configures an application container, implemented in internal/app.
+// Config configures an application container.
 type Config struct {
 	// Reverse-DNS style configured arbitrary identifier string.
-	// Passed to wayland security-context-v1 and used as part of defaults in dbus session proxy.
+	//
+	// This value is passed as is to Wayland security-context-v1 and used as
+	// part of defaults in D-Bus session proxy. The zero value causes a default
+	// value to be derived from the container instance.
 	ID string `json:"id,omitempty"`
 
 	// System services to make available in the container.
 	Enablements *Enablements `json:"enablements,omitempty"`
 
 	// Session D-Bus proxy configuration.
-	// If set to nil, session bus proxy assume built-in defaults.
+	//
+	// Has no effect if [EDBus] but is not set in Enablements. The zero value
+	// assumes built-in defaults derived from ID.
 	SessionBus *BusConfig `json:"session_bus,omitempty"`
 	// System D-Bus proxy configuration.
-	// If set to nil, system bus proxy is disabled.
+	//
+	// Has no effect if [EDBus] but is not set in Enablements. The zero value
+	// disables system bus proxy.
 	SystemBus *BusConfig `json:"system_bus,omitempty"`
 
-	// Direct access to wayland socket, no attempt is made to attach security-context-v1
-	// and the bare socket is made available to the container.
+	// Direct access to Wayland socket, no attempt is made to attach
+	// security-context-v1 and the bare socket is made available to the
+	// container.
 	//
-	// This option is unsupported and most likely enables full control over the Wayland
-	// session. Do not set this to true unless you are sure you know what you are doing.
+	// This option is unsupported and will most likely enable full control over
+	// the Wayland session from within the container. Do not set this to true
+	// unless you are sure you know what you are doing.
 	DirectWayland bool `json:"direct_wayland,omitempty"`
-	// Direct access to the PipeWire socket established via SecurityContext::Create, no
-	// attempt is made to start the pipewire-pulse server.
+
+	// Direct access to the PipeWire socket established via SecurityContext::Create,
+	// no attempt is made to start the pipewire-pulse server.
 	//
-	// The SecurityContext machinery is fatally flawed, it blindly sets read and execute
-	// bits on all objects for clients with the lowest achievable privilege level (by
-	// setting PW_KEY_ACCESS to "restricted"). This enables them to call any method
-	// targeting any object, and since Registry::Destroy checks for the read and execute bit,
-	// allows the destruction of any object other than PW_ID_CORE as well. This behaviour
-	// is implemented separately in media-session and wireplumber, with the wireplumber
-	// implementation in Lua via an embedded Lua vm. In all known setups, wireplumber is
-	// in use, and there is no known way to change its behaviour and set permissions
-	// differently without replacing the Lua script. Also, since PipeWire relies on these
-	// permissions to work, reducing them is not possible.
+	// The SecurityContext machinery is fatally flawed, it unconditionally sets
+	// read and execute bits on all objects for clients with the lowest achievable
+	// privilege level (by setting PW_KEY_ACCESS to "restricted" or by satisfying
+	// all conditions of [the /.flatpak-info hack]). This enables them to call
+	// any method targeting any object, and since Registry::Destroy checks for
+	// the read and execute bit, allows the destruction of any object other than
+	// PW_ID_CORE as well.
 	//
-	// Currently, the only other sandboxed use case is flatpak, which is not aware of
-	// PipeWire and blindly exposes the bare PulseAudio socket to the container (behaves
-	// like DirectPulse). This socket is backed by the pipewire-pulse compatibility daemon,
-	// which obtains client pid via the SO_PEERCRED option. The PipeWire daemon, pipewire-pulse
-	// daemon and the session manager daemon then separately performs the /.flatpak-info hack
-	// described in https://git.gensokyo.uk/security/hakurei/issues/21. Under such use case,
-	// since the client has no direct access to PipeWire, insecure parts of the protocol are
-	// obscured by pipewire-pulse simply not implementing them, and thus hiding the flaws
-	// described above.
+	// This behaviour is implemented separately in media-session and wireplumber,
+	// with the wireplumber implementation in Lua via an embedded Lua vm. In all
+	// known setups, wireplumber is in use, and in that case, no option for
+	// configuring this behaviour exists, without replacing the Lua script.
+	// Also, since PipeWire relies on these permissions to work, reducing them
+	// was never possible in the first place.
 	//
-	// Hakurei does not rely on the /.flatpak-info hack. Instead, a socket is sets up via
-	// SecurityContext. A pipewire-pulse server connected through it achieves the same
-	// permissions as flatpak does via the /.flatpak-info hack and is maintained for the
-	// life of the container.
+	// Currently, the only other sandboxed use case is flatpak, which is not
+	// aware of PipeWire and blindly exposes the bare PulseAudio socket to the
+	// container (behaves like DirectPulse). This socket is backed by the
+	// pipewire-pulse compatibility daemon, which obtains client pid via the
+	// SO_PEERCRED option. The PipeWire daemon, pipewire-pulse daemon and the
+	// session manager daemon then separately performs [the /.flatpak-info hack].
+	// Under such use case, since the client has no direct access to PipeWire,
+	// insecure parts of the protocol are obscured by the absence of an
+	// equivalent API in PulseAudio, or pipewire-pulse simply not implementing
+	// them.
+	//
+	// Hakurei does not rely on [the /.flatpak-info hack]. Instead, a socket is
+	// sets up via SecurityContext. A pipewire-pulse server connected through it
+	// achieves the same permissions as flatpak does via [the /.flatpak-info hack]
+	// and is maintained for the life of the container.
+	//
+	// This option is unsupported and enables a denial-of-service attack as the
+	// sandboxed client is able to destroy any client object and thus
+	// disconnecting them from PipeWire, or destroy the SecurityContext object,
+	// preventing any further container creation.
 	//
-	// This option is unsupported and enables a denial-of-service attack as the sandboxed
-	// client is able to destroy any client object and thus disconnecting them from PipeWire,
-	// or destroy the SecurityContext object preventing any further container creation.
 	// Do not set this to true, it is insecure under any configuration.
-	DirectPipeWire bool `json:"direct_pipewire,omitempty"`
-	// Direct access to PulseAudio socket, no attempt is made to establish pipewire-pulse
-	// server via a PipeWire socket with a SecurityContext attached and the bare socket
-	// is made available to the container.
 	//
-	// This option is unsupported and enables arbitrary code execution as the PulseAudio
-	// server. Do not set this to true, it is insecure under any configuration.
+	// [the /.flatpak-info hack]: https://git.gensokyo.uk/security/hakurei/issues/21
+	DirectPipeWire bool `json:"direct_pipewire,omitempty"`
+
+	// Direct access to PulseAudio socket, no attempt is made to establish
+	// pipewire-pulse server via a PipeWire socket with a SecurityContext
+	// attached, and the bare socket is made available to the container.
+	//
+	// This option is unsupported and enables arbitrary code execution as the
+	// PulseAudio server.
+	//
+	// Do not set this to true, it is insecure under any configuration.
 	DirectPulse bool `json:"direct_pulse,omitempty"`
 
 	// Extra acl updates to perform before setuid.
 	ExtraPerms []ExtraPermConfig `json:"extra_perms,omitempty"`
 
-	// Numerical application id, passed to hsu, used to derive init user namespace credentials.
+	// Numerical application id, passed to hsu, used to derive init user
+	// namespace credentials.
 	Identity int `json:"identity"`
 	// Init user namespace supplementary groups inherited by all container processes.
 	Groups []string `json:"groups"`
 
+	// Scheduling policy to set for the container.
+	//
+	// The zero value retains the current scheduling policy.
+	SchedPolicy std.SchedPolicy `json:"sched_policy,omitempty"`
+	// Scheduling priority to set for the container.
+	//
+	// The zero value implies the minimum priority of the current SchedPolicy.
+	// Has no effect if SchedPolicy is zero.
+	SchedPriority std.Int `json:"sched_priority,omitempty"`
+
 	// High level configuration applied to the underlying [container].
 	Container *ContainerConfig `json:"container"`
 }
 
 var (
-	// ErrConfigNull is returned by [Config.Validate] for an invalid configuration that contains a null value for any
-	// field that must not be null.
+	// ErrConfigNull is returned by [Config.Validate] for an invalid configuration
+	// that contains a null value for any field that must not be null.
 	ErrConfigNull = errors.New("unexpected null in config")
 
-	// ErrIdentityBounds is returned by [Config.Validate] for an out of bounds [Config.Identity] value.
+	// ErrIdentityBounds is returned by [Config.Validate] for an out of bounds
+	// [Config.Identity] value.
 	ErrIdentityBounds = errors.New("identity out of bounds")
 
-	// ErrEnviron is returned by [Config.Validate] if an environment variable name contains '=' or NUL.
+	// ErrSchedPolicyBounds is returned by [Config.Validate] for an out of bounds
+	// [Config.SchedPolicy] value.
+	ErrSchedPolicyBounds = errors.New("scheduling policy out of bounds")
+
+	// ErrEnviron is returned by [Config.Validate] if an environment variable
+	// name contains '=' or NUL.
 	ErrEnviron = errors.New("invalid environment variable name")
 
-	// ErrInsecure is returned by [Config.Validate] if the configuration is considered insecure.
+	// ErrInsecure is returned by [Config.Validate] if the configuration is
+	// considered insecure.
 	ErrInsecure = errors.New("configuration is insecure")
 )
 
@@ -112,6 +153,13 @@ func (config *Config) Validate() error {
 			Msg: "identity " + strconv.Itoa(config.Identity) + " out of range"}
 	}
 
+	if config.SchedPolicy < 0 || config.SchedPolicy > std.SCHED_LAST {
+		return &AppError{Step: "validate configuration", Err: ErrSchedPolicyBounds,
+			Msg: "scheduling policy " +
+				strconv.Itoa(int(config.SchedPolicy)) +
+				" out of range"}
+	}
+
 	if err := config.SessionBus.CheckInterfaces("session"); err != nil {
 		return err
 	}

hst/config_test.go

@@ -22,6 +22,10 @@ func TestConfigValidate(t *testing.T) {
 			Msg: "identity -1 out of range"}},
 		{"identity upper", &hst.Config{Identity: 10000}, &hst.AppError{Step: "validate configuration", Err: hst.ErrIdentityBounds,
 			Msg: "identity 10000 out of range"}},
+		{"sched lower", &hst.Config{SchedPolicy: -1}, &hst.AppError{Step: "validate configuration", Err: hst.ErrSchedPolicyBounds,
+			Msg: "scheduling policy -1 out of range"}},
+		{"sched upper", &hst.Config{SchedPolicy: 0xcafe}, &hst.AppError{Step: "validate configuration", Err: hst.ErrSchedPolicyBounds,
+			Msg: "scheduling policy 51966 out of range"}},
 		{"dbus session", &hst.Config{SessionBus: &hst.BusConfig{See: []string{""}}},
 			&hst.BadInterfaceError{Interface: "", Segment: "session"}},
 		{"dbus system", &hst.Config{SystemBus: &hst.BusConfig{See: []string{""}}},

hst/container.go

@@ -16,18 +16,20 @@ const PrivateTmp = "/.hakurei"
 var AbsPrivateTmp = check.MustAbs(PrivateTmp)
 
 const (
-	// WaitDelayDefault is used when WaitDelay has its zero value.
+	// WaitDelayDefault is used when WaitDelay has the zero value.
 	WaitDelayDefault = 5 * time.Second
-	// WaitDelayMax is used if WaitDelay exceeds its value.
+	// WaitDelayMax is used when WaitDelay exceeds its value.
 	WaitDelayMax = 30 * time.Second
 )
 
 const (
 	// ExitFailure is returned if the container fails to start.
 	ExitFailure = iota + 1
-	// ExitCancel is returned if the container is terminated by a shim-directed signal which cancels its context.
+	// ExitCancel is returned if the container is terminated by a shim-directed
+	// signal which cancels its context.
 	ExitCancel
-	// ExitOrphan is returned when the shim is orphaned before priv side delivers a signal.
+	// ExitOrphan is returned when the shim is orphaned before priv side process
+	// delivers a signal.
 	ExitOrphan
 
 	// ExitRequest is returned when the priv side process requests shim exit.
@@ -38,10 +40,12 @@ const (
 type Flags uintptr
 
 const (
-	// FMultiarch unblocks syscalls required for multiarch to work on applicable targets.
+	// FMultiarch unblocks system calls required for multiarch to work on
+	// multiarch-enabled targets (amd64, arm64).
 	FMultiarch Flags = 1 << iota
 
-	// FSeccompCompat changes emitted seccomp filter programs to be identical to that of Flatpak.
+	// FSeccompCompat changes emitted seccomp filter programs to be identical to
+	// that of Flatpak in enabled rulesets.
 	FSeccompCompat
 	// FDevel unblocks ptrace and friends.
 	FDevel
@@ -54,12 +58,15 @@ const (
 	// FTty unblocks dangerous terminal I/O (faking input).
 	FTty
 
-	// FMapRealUID maps the target user uid to the privileged user uid in the container user namespace.
-	//	Some programs fail to connect to dbus session running as a different uid,
-	//	this option works around it by mapping priv-side caller uid in container.
+	// FMapRealUID maps the target user uid to the privileged user uid in the
+	// container user namespace.
+	//
+	// Some programs fail to connect to dbus session running as a different uid,
+	// this option works around it by mapping priv-side caller uid in container.
 	FMapRealUID
 
-	// FDevice mount /dev/ from the init mount namespace as-is in the container mount namespace.
+	// FDevice mount /dev/ from the init mount namespace as is in the container
+	// mount namespace.
 	FDevice
 
 	// FShareRuntime shares XDG_RUNTIME_DIR between containers under the same identity.
@@ -112,30 +119,37 @@ func (flags Flags) String() string {
 	}
 }
 
-// ContainerConfig describes the container configuration to be applied to an underlying [container].
+// ContainerConfig describes the container configuration to be applied to an
+// underlying [container]. It is validated by [Config.Validate].
 type ContainerConfig struct {
 	// Container UTS namespace hostname.
 	Hostname string `json:"hostname,omitempty"`
 
 	// Duration in nanoseconds to wait for after interrupting the initial process.
-	// Defaults to [WaitDelayDefault] if zero, or [WaitDelayMax] if greater than [WaitDelayMax].
-	// Values lesser than zero is equivalent to zero, bypassing [WaitDelayDefault].
+	//
+	// Defaults to [WaitDelayDefault] if zero, or [WaitDelayMax] if greater than
+	// [WaitDelayMax]. Values lesser than zero is equivalent to zero, bypassing
+	// [WaitDelayDefault].
 	WaitDelay time.Duration `json:"wait_delay,omitempty"`
 
 	// Initial process environment variables.
 	Env map[string]string `json:"env"`
 
-	/* Container mount points.
-
-	If the first element targets /, it is inserted early and excluded from path hiding. */
+	// Container mount points.
+	//
+	// If the first element targets /, it is inserted early and excluded from
+	// path hiding. Otherwise, an anonymous instance of tmpfs is set up on /.
 	Filesystem []FilesystemConfigJSON `json:"filesystem"`
 
-	// String used as the username of the emulated user, validated against the default NAME_REGEX from adduser.
+	// String used as the username of the emulated user, validated against the
+	// default NAME_REGEX from adduser.
+	//
 	// Defaults to passwd name of target uid or chronos.
 	Username string `json:"username,omitempty"`
 	// Pathname of shell in the container filesystem to use for the emulated user.
 	Shell *check.Absolute `json:"shell"`
-	// Directory in the container filesystem to enter and use as the home directory of the emulated user.
+	// Directory in the container filesystem to enter and use as the home
+	// directory of the emulated user.
 	Home *check.Absolute `json:"home"`
 
 	// Pathname to executable file in the container filesystem.
@@ -148,6 +162,7 @@ type ContainerConfig struct {
 }
 
 // ContainerConfigF is [ContainerConfig] stripped of its methods.
+//
 // The [ContainerConfig.Flags] field does not survive a [json] round trip.
 type ContainerConfigF ContainerConfig
 

hst/dbus.go

@@ -5,8 +5,26 @@ import (
 	"strings"
 )
 
-// BadInterfaceError is returned when Interface fails an undocumented check in xdg-dbus-proxy,
-// which would have cause a silent failure.
+// BadInterfaceError is returned when Interface fails an undocumented check in
+// xdg-dbus-proxy, which would have cause a silent failure.
+//
+// xdg-dbus-proxy fails without output when this condition is not met:
+//
+//	char *dot = strrchr (filter->interface, '.');
+//	if (dot != NULL)
+//	  {
+//	    *dot = 0;
+//	    if (strcmp (dot + 1, "*") != 0)
+//	      filter->member = g_strdup (dot + 1);
+//	  }
+//
+// trim ".*" since they are removed before searching for '.':
+//
+//	if (g_str_has_suffix (name, ".*"))
+//	  {
+//	    name[strlen (name) - 2] = 0;
+//	    wildcard = TRUE;
+//	  }
 type BadInterfaceError struct {
 	// Interface is the offending interface string.
 	Interface string
@@ -19,7 +37,8 @@ func (e *BadInterfaceError) Error() string {
 	if e == nil {
 		return "<nil>"
 	}
-	return "bad interface string " + strconv.Quote(e.Interface) + " in " + e.Segment + " bus configuration"
+	return "bad interface string " + strconv.Quote(e.Interface) +
+		" in " + e.Segment + " bus configuration"
 }
 
 // BusConfig configures the xdg-dbus-proxy process.
@@ -76,31 +95,14 @@ func (c *BusConfig) Interfaces(yield func(string) bool) {
 	}
 }
 
-// CheckInterfaces checks for invalid interface strings based on an undocumented check in xdg-dbus-error,
-// returning [BadInterfaceError] if one is encountered.
+// CheckInterfaces checks for invalid interface strings based on an undocumented
+// check in xdg-dbus-error, returning [BadInterfaceError] if one is encountered.
 func (c *BusConfig) CheckInterfaces(segment string) error {
 	if c == nil {
 		return nil
 	}
 
 	for iface := range c.Interfaces {
-		/*
-			xdg-dbus-proxy fails without output when this condition is not met:
-				char *dot = strrchr (filter->interface, '.');
-				if (dot != NULL)
-				  {
-				    *dot = 0;
-				    if (strcmp (dot + 1, "*") != 0)
-				      filter->member = g_strdup (dot + 1);
-				  }
-
-			trim ".*" since they are removed before searching for '.':
-				if (g_str_has_suffix (name, ".*"))
-				  {
-				    name[strlen (name) - 2] = 0;
-				    wildcard = TRUE;
-				  }
-		*/
 		if strings.IndexByte(strings.TrimSuffix(iface, ".*"), '.') == -1 {
 			return &BadInterfaceError{iface, segment}
 		}

hst/enablement.go

@@ -11,15 +11,17 @@ import (
 type Enablement byte
 
 const (
-	// EWayland exposes a wayland pathname socket via security-context-v1.
+	// EWayland exposes a Wayland pathname socket via security-context-v1.
 	EWayland Enablement = 1 << iota
-	// EX11 adds the target user via X11 ChangeHosts and exposes the X11 pathname socket.
+	// EX11 adds the target user via X11 ChangeHosts and exposes the X11
+	// pathname socket.
 	EX11
 	// EDBus enables the per-container xdg-dbus-proxy daemon.
 	EDBus
 	// EPipeWire exposes a pipewire pathname socket via SecurityContext.
 	EPipeWire
-	// EPulse copies the PulseAudio cookie to [hst.PrivateTmp] and exposes the PulseAudio socket.
+	// EPulse copies the PulseAudio cookie to [hst.PrivateTmp] and exposes the
+	// PulseAudio socket.
 	EPulse
 
 	// EM is a noop.

hst/fs.go

@@ -24,7 +24,8 @@ type FilesystemConfig interface {
 	fmt.Stringer
 }
 
-// The Ops interface enables [FilesystemConfig] to queue container ops without depending on the container package.
+// The Ops interface enables [FilesystemConfig] to queue container ops without
+// depending on the container package.
 type Ops interface {
 	// Tmpfs appends an op that mounts tmpfs on a container path.
 	Tmpfs(target *check.Absolute, size int, perm os.FileMode) Ops
@@ -41,12 +42,15 @@ type Ops interface {
 	// Link appends an op that creates a symlink in the container filesystem.
 	Link(target *check.Absolute, linkName string, dereference bool) Ops
 
-	// Root appends an op that expands a directory into a toplevel bind mount mirror on container root.
+	// Root appends an op that expands a directory into a toplevel bind mount
+	// mirror on container root.
 	Root(host *check.Absolute, flags int) Ops
-	// Etc appends an op that expands host /etc into a toplevel symlink mirror with /etc semantics.
+	// Etc appends an op that expands host /etc into a toplevel symlink mirror
+	// with /etc semantics.
 	Etc(host *check.Absolute, prefix string) Ops
 
-	// Daemon appends an op that starts a daemon in the container and blocks until target appears.
+	// Daemon appends an op that starts a daemon in the container and blocks
+	// until target appears.
 	Daemon(target, path *check.Absolute, args ...string) Ops
 }
 
@@ -61,7 +65,8 @@ type ApplyState struct {
 // ErrFSNull is returned by [json] on encountering a null [FilesystemConfig] value.
 var ErrFSNull = errors.New("unexpected null in mount point")
 
-// FSTypeError is returned when [ContainerConfig.Filesystem] contains an entry with invalid type.
+// FSTypeError is returned when [ContainerConfig.Filesystem] contains an entry
+// with invalid type.
 type FSTypeError string
 
 func (f FSTypeError) Error() string { return fmt.Sprintf("invalid filesystem type %q", string(f)) }

hst/fslink.go

@@ -18,7 +18,9 @@ type FSLink struct {
 	Target *check.Absolute `json:"dst"`
 	// Arbitrary linkname value store in the symlink.
 	Linkname string `json:"linkname"`
-	// Whether to treat Linkname as an absolute pathname and dereference before creating the link.
+
+	// Whether to treat Linkname as an absolute pathname and dereference before
+	// creating the link.
 	Dereference bool `json:"dereference,omitempty"`
 }
 

hst/fsoverlay.go

@@ -19,9 +19,11 @@ type FSOverlay struct {
 
 	// Any filesystem, does not need to be on a writable filesystem, must not be nil.
 	Lower []*check.Absolute `json:"lower"`
-	// The upperdir is normally on a writable filesystem, leave as nil to mount Lower readonly.
+	// The upperdir is normally on a writable filesystem, leave as nil to mount
+	// Lower readonly.
 	Upper *check.Absolute `json:"upper,omitempty"`
-	// The workdir needs to be an empty directory on the same filesystem as Upper, must not be nil if Upper is populated.
+	// The workdir needs to be an empty directory on the same filesystem as
+	// Upper, must not be nil if Upper is populated.
 	Work *check.Absolute `json:"work,omitempty"`
 }
 

hst/hst.go

@@ -44,11 +44,13 @@ func (e *AppError) Message() string {
 type Paths struct {
 	// Temporary directory returned by [os.TempDir], usually equivalent to [fhs.AbsTmp].
 	TempDir *check.Absolute `json:"temp_dir"`
-	// Shared directory specific to the hsu userid, usually (`/tmp/hakurei.%d`, [Info.User]).
+	// Shared directory specific to the hsu userid, usually
+	// (`/tmp/hakurei.%d`, [Info.User]).
 	SharePath *check.Absolute `json:"share_path"`
 	// Checked XDG_RUNTIME_DIR value, usually (`/run/user/%d`, uid).
 	RuntimePath *check.Absolute `json:"runtime_path"`
-	// Shared directory specific to the hsu userid located in RuntimePath, usually (`/run/user/%d/hakurei`, uid).
+	// Shared directory specific to the hsu userid located in RuntimePath,
+	// usually (`/run/user/%d/hakurei`, uid).
 	RunDirPath *check.Absolute `json:"run_dir_path"`
 }
 
@@ -74,10 +76,23 @@ func Template() *Config {
 
 		SessionBus: &BusConfig{
 			See: nil,
-			Talk: []string{"org.freedesktop.Notifications", "org.freedesktop.FileManager1", "org.freedesktop.ScreenSaver",
-				"org.freedesktop.secrets", "org.kde.kwalletd5", "org.kde.kwalletd6", "org.gnome.SessionManager"},
-			Own: []string{"org.chromium.Chromium.*", "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-				"org.mpris.MediaPlayer2.chromium.*"},
+			Talk: []string{
+				"org.freedesktop.Notifications",
+				"org.freedesktop.FileManager1",
+				"org.freedesktop.ScreenSaver",
+				"org.freedesktop.secrets",
+
+				"org.kde.kwalletd5",
+				"org.kde.kwalletd6",
+
+				"org.gnome.SessionManager",
+			},
+			Own: []string{
+				"org.chromium.Chromium.*",
+
+				"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+				"org.mpris.MediaPlayer2.chromium.*",
+			},
 			Call:      map[string]string{"org.freedesktop.portal.*": "*"},
 			Broadcast: map[string]string{"org.freedesktop.portal.*": "@/org/freedesktop/portal/*"},
 			Log:       false,
@@ -112,7 +127,12 @@ func Template() *Config {
 				"GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT",
 			},
 			Filesystem: []FilesystemConfigJSON{
-				{&FSBind{Target: fhs.AbsRoot, Source: fhs.AbsVarLib.Append("hakurei/base/org.debian"), Write: true, Special: true}},
+				{&FSBind{
+					Target:  fhs.AbsRoot,
+					Source:  fhs.AbsVarLib.Append("hakurei/base/org.debian"),
+					Write:   true,
+					Special: true,
+				}},
 				{&FSBind{Target: fhs.AbsEtc, Source: fhs.AbsEtc, Special: true}},
 				{&FSEphemeral{Target: fhs.AbsTmp, Write: true, Perm: 0755}},
 				{&FSOverlay{
@@ -121,11 +141,27 @@ func Template() *Config {
 					Upper:  fhs.AbsVarLib.Append("hakurei/nix/u0/org.chromium.Chromium/rw-store/upper"),
 					Work:   fhs.AbsVarLib.Append("hakurei/nix/u0/org.chromium.Chromium/rw-store/work"),
 				}},
-				{&FSLink{Target: fhs.AbsRun.Append("current-system"), Linkname: "/run/current-system", Dereference: true}},
-				{&FSLink{Target: fhs.AbsRun.Append("opengl-driver"), Linkname: "/run/opengl-driver", Dereference: true}},
-				{&FSBind{Source: fhs.AbsVarLib.Append("hakurei/u0/org.chromium.Chromium"),
-					Target: check.MustAbs("/data/data/org.chromium.Chromium"), Write: true, Ensure: true}},
-				{&FSBind{Source: fhs.AbsDev.Append("dri"), Device: true, Optional: true}},
+				{&FSLink{
+					Target:      fhs.AbsRun.Append("current-system"),
+					Linkname:    "/run/current-system",
+					Dereference: true,
+				}},
+				{&FSLink{
+					Target:      fhs.AbsRun.Append("opengl-driver"),
+					Linkname:    "/run/opengl-driver",
+					Dereference: true,
+				}},
+				{&FSBind{
+					Source: fhs.AbsVarLib.Append("hakurei/u0/org.chromium.Chromium"),
+					Target: check.MustAbs("/data/data/org.chromium.Chromium"),
+					Write:  true,
+					Ensure: true,
+				}},
+				{&FSBind{
+					Source:   fhs.AbsDev.Append("dri"),
+					Device:   true,
+					Optional: true,
+				}},
 			},
 
 			Username: "chronos",

hst/instance.go

@@ -12,10 +12,12 @@ import (
 // An ID is a unique identifier held by a running hakurei container.
 type ID [16]byte
 
-// ErrIdentifierLength is returned when encountering a [hex] representation of [ID] with unexpected length.
+// ErrIdentifierLength is returned when encountering a [hex] representation of
+// [ID] with unexpected length.
 var ErrIdentifierLength = errors.New("identifier string has unexpected length")
 
-// IdentifierDecodeError is returned by [ID.UnmarshalText] to provide relevant error descriptions.
+// IdentifierDecodeError is returned by [ID.UnmarshalText] to provide relevant
+// error descriptions.
 type IdentifierDecodeError struct{ Err error }
 
 func (e IdentifierDecodeError) Unwrap() error { return e.Err }
@@ -23,7 +25,10 @@ func (e IdentifierDecodeError) Error() string {
 	var invalidByteError hex.InvalidByteError
 	switch {
 	case errors.As(e.Err, &invalidByteError):
-		return fmt.Sprintf("got invalid byte %#U in identifier", rune(invalidByteError))
+		return fmt.Sprintf(
+			"got invalid byte %#U in identifier",
+			rune(invalidByteError),
+		)
 	case errors.Is(e.Err, hex.ErrLength):
 		return "odd length identifier hex string"
 
@@ -41,7 +46,9 @@ func (a *ID) CreationTime() time.Time {
 }
 
 // NewInstanceID creates a new unique [ID].
-func NewInstanceID(id *ID) error { return newInstanceID(id, uint64(time.Now().UnixNano())) }
+func NewInstanceID(id *ID) error {
+	return newInstanceID(id, uint64(time.Now().UnixNano()))
+}
 
 // newInstanceID creates a new unique [ID] with the specified timestamp.
 func newInstanceID(id *ID, p uint64) error {

internal/lockedfile/internal/filelock/filelock.go

@@ -8,7 +8,6 @@
 package filelock
 
 import (
-	"errors"
 	"io/fs"
 )
 
@@ -74,10 +73,3 @@ func (lt lockType) String() string {
 		return "Unlock"
 	}
 }
-
-// IsNotSupported returns a boolean indicating whether the error is known to
-// report that a function is not supported (possibly for a specific input).
-// It is satisfied by errors.ErrUnsupported as well as some syscall errors.
-func IsNotSupported(err error) bool {
-	return errors.Is(err, errors.ErrUnsupported)
-}

internal/lockedfile/internal/filelock/filelock_test.go

@@ -14,7 +14,7 @@ import (
 	"testing"
 	"time"
 
-	"hakurei.app/container"
+	"hakurei.app/container/fhs"
 	"hakurei.app/internal/lockedfile/internal/filelock"
 	"hakurei.app/internal/lockedfile/internal/testexec"
 )
@@ -197,7 +197,7 @@ func TestLockNotDroppedByExecCommand(t *testing.T) {
 	// Some kinds of file locks are dropped when a duplicated or forked file
 	// descriptor is unlocked. Double-check that the approach used by os/exec does
 	// not accidentally drop locks.
-	cmd := testexec.CommandContext(t, t.Context(), container.MustExecutable(nil), "-test.run=^$")
+	cmd := testexec.CommandContext(t, t.Context(), fhs.ProcSelfExe, "-test.run=^$")
 	if err := cmd.Run(); err != nil {
 		t.Fatalf("exec failed: %v", err)
 	}

internal/lockedfile/lockedfile.go

@@ -94,6 +94,11 @@ func (f *File) Close() error {
 
 	err := closeFile(f.osFile.File)
 	f.cleanup.Stop()
+	// f may be dead at the moment after we access f.cleanup,
+	// so the cleanup can fire before Stop completes. Keep f
+	// alive while we call Stop. See the documentation for
+	// runtime.Cleanup.Stop.
+	runtime.KeepAlive(f)
 	return err
 }
 

internal/lockedfile/lockedfile_test.go

@@ -15,7 +15,7 @@ import (
 	"testing"
 	"time"
 
-	"hakurei.app/container"
+	"hakurei.app/container/fhs"
 	"hakurei.app/internal/lockedfile"
 	"hakurei.app/internal/lockedfile/internal/testexec"
 )
@@ -215,7 +215,7 @@ func TestSpuriousEDEADLK(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	cmd := testexec.CommandContext(t, t.Context(), container.MustExecutable(nil), "-test.run=^"+t.Name()+"$")
+	cmd := testexec.CommandContext(t, t.Context(), fhs.ProcSelfExe, "-test.run=^"+t.Name()+"$")
 	cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%s", dirVar, dir))
 
 	qDone := make(chan struct{})

internal/outcome/hsu.go

@@ -38,6 +38,7 @@ func (h *Hsu) ensureDispatcher() {
 }
 
 // ID returns the current user hsurc identifier.
+//
 // [ErrHsuAccess] is returned if the current user is not in hsurc.
 func (h *Hsu) ID() (int, error) {
 	h.ensureDispatcher()

internal/outcome/outcome.go

@@ -1,4 +1,5 @@
-// Package outcome implements the outcome of the privileged and container sides of a hakurei container.
+// Package outcome implements the outcome of the privileged and container sides
+// of a hakurei container.
 package outcome
 
 import (
@@ -27,8 +28,9 @@ func Info() *hst.Info {
 	return &hi
 }
 
-// envAllocSize is the initial size of the env map pre-allocated when the configured env map is nil.
-// It should be large enough to fit all insertions by outcomeOp.toContainer.
+// envAllocSize is the initial size of the env map pre-allocated when the
+// configured env map is nil. It should be large enough to fit all insertions by
+// outcomeOp.toContainer.
 const envAllocSize = 1 << 6
 
 func newInt(v int) *stringPair[int] { return &stringPair[int]{v, strconv.Itoa(v)} }
@@ -43,7 +45,8 @@ func (s *stringPair[T]) unwrap() T      { return s.v }
 func (s *stringPair[T]) String() string { return s.s }
 
 // outcomeState is copied to the shim process and available while applying outcomeOp.
-// This is transmitted from the priv side to the shim, so exported fields should be kept to a minimum.
+// This is transmitted from the priv side to the shim, so exported fields should
+// be kept to a minimum.
 type outcomeState struct {
 	// Params only used by the shim process. Populated by populateEarly.
 	Shim *shimParams
@@ -89,14 +92,25 @@ func (s *outcomeState) valid() bool {
 		s.Paths != nil
 }
 
-// newOutcomeState returns the address of a new outcomeState with its exported fields populated via syscallDispatcher.
+// newOutcomeState returns the address of a new outcomeState with its exported
+// fields populated via syscallDispatcher.
 func newOutcomeState(k syscallDispatcher, msg message.Msg, id *hst.ID, config *hst.Config, hsu *Hsu) *outcomeState {
 	s := outcomeState{
-		Shim:      &shimParams{PrivPID: k.getpid(), Verbose: msg.IsVerbose()},
-		ID:        id,
-		Identity:  config.Identity,
-		UserID:    hsu.MustID(msg),
-		Paths:     env.CopyPathsFunc(k.fatalf, k.tempdir, func(key string) string { v, _ := k.lookupEnv(key); return v }),
+		Shim: &shimParams{
+			PrivPID: k.getpid(),
+			Verbose: msg.IsVerbose(),
+
+			SchedPolicy:   config.SchedPolicy,
+			SchedPriority: config.SchedPriority,
+		},
+
+		ID:       id,
+		Identity: config.Identity,
+		UserID:   hsu.MustID(msg),
+		Paths: env.CopyPathsFunc(k.fatalf, k.tempdir, func(key string) string {
+			v, _ := k.lookupEnv(key)
+			return v
+		}),
 		Container: config.Container,
 	}
 
@@ -121,6 +135,7 @@ func newOutcomeState(k syscallDispatcher, msg message.Msg, id *hst.ID, config *h
 }
 
 // populateLocal populates unexported fields from transmitted exported fields.
+//
 // These fields are cheaper to recompute per-process.
 func (s *outcomeState) populateLocal(k syscallDispatcher, msg message.Msg) error {
 	if !s.valid() || k == nil || msg == nil {
@@ -136,7 +151,10 @@ func (s *outcomeState) populateLocal(k syscallDispatcher, msg message.Msg) error
 	s.id = &stringPair[hst.ID]{*s.ID, s.ID.String()}
 
 	s.Copy(&s.sc, s.UserID)
-	msg.Verbosef("process share directory at %q, runtime directory at %q", s.sc.SharePath, s.sc.RunDirPath)
+	msg.Verbosef(
+		"process share directory at %q, runtime directory at %q",
+		s.sc.SharePath, s.sc.RunDirPath,
+	)
 
 	s.identity = newInt(s.Identity)
 	s.mapuid, s.mapgid = newInt(s.Mapuid), newInt(s.Mapgid)
@@ -146,17 +164,25 @@ func (s *outcomeState) populateLocal(k syscallDispatcher, msg message.Msg) error
 }
 
 // instancePath returns a path formatted for outcomeStateSys.instance.
+//
 // This method must only be called from outcomeOp.toContainer if
 // outcomeOp.toSystem has already called outcomeStateSys.instance.
-func (s *outcomeState) instancePath() *check.Absolute { return s.sc.SharePath.Append(s.id.String()) }
+func (s *outcomeState) instancePath() *check.Absolute {
+	return s.sc.SharePath.Append(s.id.String())
+}
 
 // runtimePath returns a path formatted for outcomeStateSys.runtime.
+//
 // This method must only be called from outcomeOp.toContainer if
 // outcomeOp.toSystem has already called outcomeStateSys.runtime.
-func (s *outcomeState) runtimePath() *check.Absolute { return s.sc.RunDirPath.Append(s.id.String()) }
+func (s *outcomeState) runtimePath() *check.Absolute {
+	return s.sc.RunDirPath.Append(s.id.String())
+}
 
 // outcomeStateSys wraps outcomeState and [system.I]. Used on the priv side only.
-// Implementations of outcomeOp must not access fields other than sys unless explicitly stated.
+//
+// Implementations of outcomeOp must not access fields other than sys unless
+// explicitly stated.
 type outcomeStateSys struct {
 	// Whether XDG_RUNTIME_DIR is used post hsu.
 	useRuntimeDir bool
@@ -219,6 +245,7 @@ func (state *outcomeStateSys) ensureRuntimeDir() {
 }
 
 // instance returns the pathname to a process-specific directory within TMPDIR.
+//
 // This directory must only hold entries bound to [system.Process].
 func (state *outcomeStateSys) instance() *check.Absolute {
 	if state.sharePath != nil {
@@ -230,6 +257,7 @@ func (state *outcomeStateSys) instance() *check.Absolute {
 }
 
 // runtime returns the pathname to a process-specific directory within XDG_RUNTIME_DIR.
+//
 // This directory must only hold entries bound to [system.Process].
 func (state *outcomeStateSys) runtime() *check.Absolute {
 	if state.runtimeSharePath != nil {
@@ -242,22 +270,29 @@ func (state *outcomeStateSys) runtime() *check.Absolute {
 	return state.runtimeSharePath
 }
 
-// outcomeStateParams wraps outcomeState and [container.Params]. Used on the shim side only.
+// outcomeStateParams wraps outcomeState and [container.Params].
+//
+// Used on the shim side only.
 type outcomeStateParams struct {
-	// Overrides the embedded [container.Params] in [container.Container]. The Env field must not be used.
+	// Overrides the embedded [container.Params] in [container.Container].
+	//
+	// The Env field must not be used.
 	params *container.Params
 	// Collapsed into the Env slice in [container.Params] by the final outcomeOp.
 	env map[string]string
 
-	// Filesystems with the optional root sliced off if present. Populated by spParamsOp.
-	// Safe for use by spFilesystemOp.
+	// Filesystems with the optional root sliced off if present.
+	//
+	// Populated by spParamsOp. Safe for use by spFilesystemOp.
 	filesystem []hst.FilesystemConfigJSON
 
 	// Inner XDG_RUNTIME_DIR default formatting of `/run/user/%d` via mapped uid.
+	//
 	// Populated by spRuntimeOp.
 	runtimeDir *check.Absolute
 
 	// Path to pipewire-pulse server.
+	//
 	// Populated by spPipeWireOp if DirectPipeWire is false.
 	pipewirePulsePath *check.Absolute
 
@@ -265,25 +300,32 @@ type outcomeStateParams struct {
 	*outcomeState
 }
 
-// errNotEnabled is returned by outcomeOp.toSystem and used internally to exclude an outcomeOp from transmission.
+// errNotEnabled is returned by outcomeOp.toSystem and used internally to
+// exclude an outcomeOp from transmission.
 var errNotEnabled = errors.New("op not enabled in the configuration")
 
-// An outcomeOp inflicts an outcome on [system.I] and contains enough information to
-// inflict it on [container.Params] in a separate process.
-// An implementation of outcomeOp must store cross-process states in exported fields only.
+// An outcomeOp inflicts an outcome on [system.I] and contains enough
+// information to inflict it on [container.Params] in a separate process.
+//
+// An implementation of outcomeOp must store cross-process states in exported
+// fields only.
 type outcomeOp interface {
 	// toSystem inflicts the current outcome on [system.I] in the priv side process.
 	toSystem(state *outcomeStateSys) error
 
-	// toContainer inflicts the current outcome on [container.Params] in the shim process.
-	// The implementation must not write to the Env field of [container.Params] as it will be overwritten
-	// by flattened env map.
+	// toContainer inflicts the current outcome on [container.Params] in the
+	// shim process.
+	//
+	// Implementations must not write to the Env field of [container.Params]
+	// as it will be overwritten by flattened env map.
 	toContainer(state *outcomeStateParams) error
 }
 
-// toSystem calls the outcomeOp.toSystem method on all outcomeOp implementations and populates shimParams.Ops.
-// This function assumes the caller has already called the Validate method on [hst.Config]
-// and checked that it returns nil.
+// toSystem calls the outcomeOp.toSystem method on all outcomeOp implementations
+// and populates shimParams.Ops.
+//
+// This function assumes the caller has already called the Validate method on
+// [hst.Config] and checked that it returns nil.
 func (state *outcomeStateSys) toSystem() error {
 	if state.Shim == nil || state.Shim.Ops != nil {
 		return newWithMessage("invalid ops state reached")

internal/outcome/process.go

@@ -30,7 +30,9 @@ const (
 )
 
 // NewStore returns the address of a new instance of [store.Store].
-func NewStore(sc *hst.Paths) *store.Store { return store.New(sc.SharePath.Append("state")) }
+func NewStore(sc *hst.Paths) *store.Store {
+	return store.New(sc.SharePath.Append("state"))
+}
 
 // main carries out outcome and terminates. main does not return.
 func (k *outcome) main(msg message.Msg, identifierFd int) {
@@ -116,7 +118,11 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 		processStatePrev, processStateCur = processStateCur, processState
 
 		if !processTime.IsZero() && processStatePrev != processLifecycle {
-			msg.Verbosef("state %d took %.2f ms", processStatePrev, float64(time.Since(processTime).Nanoseconds())/1e6)
+			msg.Verbosef(
+				"state %d took %.2f ms",
+				processStatePrev,
+				float64(time.Since(processTime).Nanoseconds())/1e6,
+			)
 		}
 		processTime = time.Now()
 
@@ -141,7 +147,10 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 
 		case processCommit:
 			if isBeforeRevert {
-				perrorFatal(newWithMessage("invalid transition to commit state"), "commit", processLifecycle)
+				perrorFatal(
+					newWithMessage("invalid transition to commit state"),
+					"commit", processLifecycle,
+				)
 				continue
 			}
 
@@ -238,15 +247,26 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 
 			case <-func() chan struct{} {
 				w := make(chan struct{})
-				// this ties processLifecycle to ctx with the additional compensated timeout duration
-				// to allow transition to the next state on a locked up shim
-				go func() { <-ctx.Done(); time.Sleep(k.state.Shim.WaitDelay + shimWaitTimeout); close(w) }()
+				// This ties processLifecycle to ctx with the additional
+				// compensated timeout duration to allow transition to the next
+				// state on a locked up shim.
+				go func() {
+					<-ctx.Done()
+					time.Sleep(k.state.Shim.WaitDelay + shimWaitTimeout)
+					close(w)
+				}()
 				return w
 			}():
-				// this is only reachable when wait did not return within shimWaitTimeout, after its WaitDelay has elapsed.
-				// This is different from the container failing to terminate within its timeout period, as that is enforced
-				// by the shim. This path is instead reached when there is a lockup in shim preventing it from completing.
-				msg.GetLogger().Printf("process %d did not terminate", shimCmd.Process.Pid)
+				// This is only reachable when wait did not return within
+				// shimWaitTimeout, after its WaitDelay has elapsed. This is
+				// different from the container failing to terminate within its
+				// timeout period, as that is enforced by the shim. This path is
+				// instead reached when there is a lockup in shim preventing it
+				// from completing.
+				msg.GetLogger().Printf(
+					"process %d did not terminate",
+					shimCmd.Process.Pid,
+				)
 			}
 			msg.Resume()
 
@@ -271,8 +291,8 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 				ec := system.Process
 
 				if entries, _, err := handle.Entries(); err != nil {
-					// it is impossible to continue from this point,
-					// per-process state will be reverted to limit damage
+					// it is impossible to continue from this point, per-process
+					// state will be reverted to limit damage
 					perror(err, "read store segment entries")
 				} else {
 					// accumulate enablements of remaining instances
@@ -295,7 +315,10 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 					if n == 0 {
 						ec |= system.User
 					} else {
-						msg.Verbosef("found %d instances, cleaning up without user-scoped operations", n)
+						msg.Verbosef(
+							"found %d instances, cleaning up without user-scoped operations",
+							n,
+						)
 					}
 					ec |= rt ^ (hst.EWayland | hst.EX11 | hst.EDBus | hst.EPulse)
 					if msg.IsVerbose() {
@@ -335,7 +358,9 @@ func (k *outcome) main(msg message.Msg, identifierFd int) {
 
 // start starts the shim via cmd/hsu.
 //
-// If successful, a [time.Time] value for [hst.State] is stored in the value pointed to by startTime.
+// If successful, a [time.Time] value for [hst.State] is stored in the value
+// pointed to by startTime.
+//
 // The resulting [exec.Cmd] and write end of the shim setup pipe is returned.
 func (k *outcome) start(ctx context.Context, msg message.Msg,
 	hsuPath *check.Absolute,

internal/outcome/shim.go

@@ -37,9 +37,12 @@ const (
 	shimMsgBadPID = C.HAKUREI_SHIM_BAD_PID
 )
 
-// setupContSignal sets up the SIGCONT signal handler for the cross-uid shim exit hack.
-// The signal handler is implemented in C, signals can be processed by reading from the returned reader.
-// The returned function must be called after all signal processing concludes.
+// setupContSignal sets up the SIGCONT signal handler for the cross-uid shim
+// exit hack.
+//
+// The signal handler is implemented in C, signals can be processed by reading
+// from the returned reader. The returned function must be called after all
+// signal processing concludes.
 func setupContSignal(pid int) (io.ReadCloser, func(), error) {
 	if r, w, err := os.Pipe(); err != nil {
 		return nil, nil, err
@@ -51,22 +54,30 @@ func setupContSignal(pid int) (io.ReadCloser, func(), error) {
 	}
 }
 
-// shimEnv is the name of the environment variable storing decimal representation of
-// setup pipe fd for [container.Receive].
+// shimEnv is the name of the environment variable storing decimal representation
+// of setup pipe fd for [container.Receive].
 const shimEnv = "HAKUREI_SHIM"
 
 // shimParams is embedded in outcomeState and transmitted from priv side to shim.
 type shimParams struct {
-	// Priv side pid, checked against ppid in signal handler for the syscall.SIGCONT hack.
+	// Priv side pid, checked against ppid in signal handler for the
+	// syscall.SIGCONT hack.
 	PrivPID int
 
-	// Duration to wait for after the initial process receives os.Interrupt before the container is killed.
+	// Duration to wait for after the initial process receives os.Interrupt
+	// before the container is killed.
+	//
 	// Limits are enforced on the priv side.
 	WaitDelay time.Duration
 
 	// Verbosity pass through from [message.Msg].
 	Verbose bool
 
+	// Copied from [hst.Config].
+	SchedPolicy std.SchedPolicy
+	// Copied from [hst.Config].
+	SchedPriority std.Int
+
 	// Outcome setup ops, contains setup state. Populated by outcome.finalise.
 	Ops []outcomeOp
 }
@@ -77,7 +88,9 @@ func (p *shimParams) valid() bool { return p != nil && p.PrivPID > 0 }
 // shimName is the prefix used by log.std in the shim process.
 const shimName = "shim"
 
-// Shim is called by the main function of the shim process and runs as the unconstrained target user.
+// Shim is called by the main function of the shim process and runs as the
+// unconstrained target user.
+//
 // Shim does not return.
 func Shim(msg message.Msg) {
 	if msg == nil {
@@ -131,7 +144,8 @@ func (sp *shimPrivate) destroy() {
 }
 
 const (
-	// shimPipeWireTimeout is the duration pipewire-pulse is allowed to run before its socket becomes available.
+	// shimPipeWireTimeout is the duration pipewire-pulse is allowed to run
+	// before its socket becomes available.
 	shimPipeWireTimeout = 5 * time.Second
 )
 
@@ -262,6 +276,9 @@ func shimEntrypoint(k syscallDispatcher) {
 	cancelContainer.Store(&stop)
 	sp := shimPrivate{k: k, id: state.id}
 	z := container.New(ctx, msg)
+	z.SetScheduler = state.Shim.SchedPolicy > 0
+	z.SchedPolicy = state.Shim.SchedPolicy
+	z.SchedPriority = state.Shim.SchedPriority
 	z.Params = *stateParams.params
 	z.Stdin, z.Stdout, z.Stderr = os.Stdin, os.Stdout, os.Stderr
 

internal/outcome/spcontainer.go

@@ -27,7 +27,9 @@ const varRunNscd = fhs.Var + "run/nscd"
 
 func init() { gob.Register(new(spParamsOp)) }
 
-// spParamsOp initialises unordered fields of [container.Params] and the optional root filesystem.
+// spParamsOp initialises unordered fields of [container.Params] and the
+// optional root filesystem.
+//
 // This outcomeOp is hardcoded to always run first.
 type spParamsOp struct {
 	// Value of $TERM, stored during toSystem.
@@ -67,8 +69,8 @@ func (s *spParamsOp) toContainer(state *outcomeStateParams) error {
 		state.params.Args = state.Container.Args
 	}
 
-	// the container is canceled when shim is requested to exit or receives an interrupt or termination signal;
-	// this behaviour is implemented in the shim
+	// The container is cancelled when shim is requested to exit or receives an
+	// interrupt or termination signal. This behaviour is implemented in the shim.
 	state.params.ForwardCancel = state.Shim.WaitDelay > 0
 
 	if state.Container.Flags&hst.FMultiarch != 0 {
@@ -115,7 +117,8 @@ func (s *spParamsOp) toContainer(state *outcomeStateParams) error {
 	} else {
 		state.params.Bind(fhs.AbsDev, fhs.AbsDev, std.BindWritable|std.BindDevice)
 	}
-	// /dev is mounted readonly later on, this prevents /dev/shm from going readonly with it
+	// /dev is mounted readonly later on, this prevents /dev/shm from going
+	// readonly with it
 	state.params.Tmpfs(fhs.AbsDevShm, 0, 01777)
 
 	return nil
@@ -123,7 +126,9 @@ func (s *spParamsOp) toContainer(state *outcomeStateParams) error {
 
 func init() { gob.Register(new(spFilesystemOp)) }
 
-// spFilesystemOp applies configured filesystems to [container.Params], excluding the optional root filesystem.
+// spFilesystemOp applies configured filesystems to [container.Params],
+// excluding the optional root filesystem.
+//
 // This outcomeOp is hardcoded to always run last.
 type spFilesystemOp struct {
 	// Matched paths to cover. Stored during toSystem.
@@ -297,8 +302,8 @@ func (s *spFilesystemOp) toContainer(state *outcomeStateParams) error {
 	return nil
 }
 
-// resolveRoot handles the root filesystem special case for [hst.FilesystemConfig] and additionally resolves autoroot
-// as it requires special handling during path hiding.
+// resolveRoot handles the root filesystem special case for [hst.FilesystemConfig]
+// and additionally resolves autoroot as it requires special handling during path hiding.
 func resolveRoot(c *hst.ContainerConfig) (rootfs hst.FilesystemConfig, filesystem []hst.FilesystemConfigJSON, autoroot *hst.FSBind) {
 	// root filesystem special case
 	filesystem = c.Filesystem
@@ -316,7 +321,8 @@ func resolveRoot(c *hst.ContainerConfig) (rootfs hst.FilesystemConfig, filesyste
 	return
 }
 
-// evalSymlinks calls syscallDispatcher.evalSymlinks but discards errors unwrapping to [fs.ErrNotExist].
+// evalSymlinks calls syscallDispatcher.evalSymlinks but discards errors
+// unwrapping to [fs.ErrNotExist].
 func evalSymlinks(msg message.Msg, k syscallDispatcher, v *string) error {
 	if p, err := k.evalSymlinks(*v); err != nil {
 		if !errors.Is(err, fs.ErrNotExist) {

internal/outcome/spdbus.go

@@ -12,6 +12,7 @@ import (
 func init() { gob.Register(new(spDBusOp)) }
 
 // spDBusOp maintains an xdg-dbus-proxy instance for the container.
+//
 // Runs after spRuntimeOp.
 type spDBusOp struct {
 	// Whether to bind the system bus socket. Populated during toSystem.

internal/outcome/sppipewire.go

@@ -13,9 +13,12 @@ const pipewirePulseName = "pipewire-pulse"
 func init() { gob.Register(new(spPipeWireOp)) }
 
 // spPipeWireOp exports the PipeWire server to the container via SecurityContext.
+//
 // Runs after spRuntimeOp.
 type spPipeWireOp struct {
-	// Path to pipewire-pulse server. Populated during toSystem if DirectPipeWire is false.
+	// Path to pipewire-pulse server.
+	//
+	// Populated during toSystem if DirectPipeWire is false.
 	CompatServerPath *check.Absolute
 }
 

internal/outcome/sppulse.go

@@ -20,6 +20,7 @@ const pulseCookieSizeMax = 1 << 8
 func init() { gob.Register(new(spPulseOp)) }
 
 // spPulseOp exports the PulseAudio server to the container.
+//
 // Runs after spRuntimeOp.
 type spPulseOp struct {
 	// PulseAudio cookie data, populated during toSystem if a cookie is present.
@@ -37,24 +38,40 @@ func (s *spPulseOp) toSystem(state *outcomeStateSys) error {
 
 	if _, err := state.k.stat(pulseRuntimeDir.String()); err != nil {
 		if !errors.Is(err, fs.ErrNotExist) {
-			return &hst.AppError{Step: fmt.Sprintf("access PulseAudio directory %q", pulseRuntimeDir), Err: err}
+			return &hst.AppError{Step: fmt.Sprintf(
+				"access PulseAudio directory %q",
+				pulseRuntimeDir,
+			), Err: err}
 		}
-		return newWithMessageError(fmt.Sprintf("PulseAudio directory %q not found", pulseRuntimeDir), err)
+		return newWithMessageError(fmt.Sprintf(
+			"PulseAudio directory %q not found",
+			pulseRuntimeDir,
+		), err)
 	}
 
 	if fi, err := state.k.stat(pulseSocket.String()); err != nil {
 		if !errors.Is(err, fs.ErrNotExist) {
-			return &hst.AppError{Step: fmt.Sprintf("access PulseAudio socket %q", pulseSocket), Err: err}
+			return &hst.AppError{Step: fmt.Sprintf(
+				"access PulseAudio socket %q",
+				pulseSocket,
+			), Err: err}
 		}
-		return newWithMessageError(fmt.Sprintf("PulseAudio directory %q found but socket does not exist", pulseRuntimeDir), err)
+		return newWithMessageError(fmt.Sprintf(
+			"PulseAudio directory %q found but socket does not exist",
+			pulseRuntimeDir,
+		), err)
 	} else {
 		if m := fi.Mode(); m&0o006 != 0o006 {
-			return newWithMessage(fmt.Sprintf("unexpected permissions on %q: %s", pulseSocket, m))
+			return newWithMessage(fmt.Sprintf(
+				"unexpected permissions on %q: %s",
+				pulseSocket, m,
+			))
 		}
 	}
 
-	// pulse socket is world writable and its parent directory DAC permissions prevents access;
-	// hard link to target-executable share directory to grant access
+	// PulseAudio socket is world writable and its parent directory DAC
+	// permissions prevents access. Hard link to target-executable share
+	// directory to grant access
 	state.sys.Link(pulseSocket, state.runtime().Append("pulse"))
 
 	// load up to pulseCookieSizeMax bytes of pulse cookie for transmission to shim
@@ -62,7 +79,13 @@ func (s *spPulseOp) toSystem(state *outcomeStateSys) error {
 		return err
 	} else if a != nil {
 		s.Cookie = new([pulseCookieSizeMax]byte)
-		if s.CookieSize, err = loadFile(state.msg, state.k, "PulseAudio cookie", a.String(), s.Cookie[:]); err != nil {
+		if s.CookieSize, err = loadFile(
+			state.msg,
+			state.k,
+			"PulseAudio cookie",
+			a.String(),
+			s.Cookie[:],
+		); err != nil {
 			return err
 		}
 	} else {
@@ -101,8 +124,9 @@ func (s *spPulseOp) commonPaths(state *outcomeState) (pulseRuntimeDir, pulseSock
 	return
 }
 
-// discoverPulseCookie attempts to discover the pathname of the PulseAudio cookie of the current user.
-// If both returned pathname and error are nil, the cookie is likely unavailable and can be silently skipped.
+// discoverPulseCookie attempts to discover the pathname of the PulseAudio
+// cookie of the current user. If both returned pathname and error are nil, the
+// cookie is likely unavailable and can be silently skipped.
 func discoverPulseCookie(k syscallDispatcher) (*check.Absolute, error) {
 	const paLocateStep = "locate PulseAudio cookie"
 
@@ -186,7 +210,10 @@ func loadFile(
 				&os.PathError{Op: "stat", Path: pathname, Err: syscall.ENOMEM},
 			)
 		} else if s < int64(n) {
-			msg.Verbosef("%s at %q is %d bytes shorter than expected", description, pathname, int64(n)-s)
+			msg.Verbosef(
+				"%s at %q is %d bytes shorter than expected",
+				description, pathname, int64(n)-s,
+			)
 		} else {
 			msg.Verbosef("loading %d bytes from %q", n, pathname)
 		}

internal/outcome/spruntime.go

@@ -67,7 +67,9 @@ const (
 
 // spRuntimeOp sets up XDG_RUNTIME_DIR inside the container.
 type spRuntimeOp struct {
-	// SessionType determines the value of envXDGSessionType. Populated during toSystem.
+	// SessionType determines the value of envXDGSessionType.
+	//
+	// Populated during toSystem.
 	SessionType uintptr
 }
 

internal/outcome/spwayland.go

@@ -12,9 +12,12 @@ import (
 func init() { gob.Register(new(spWaylandOp)) }
 
 // spWaylandOp exports the Wayland display server to the container.
+//
 // Runs after spRuntimeOp.
 type spWaylandOp struct {
-	// Path to host wayland socket. Populated during toSystem if DirectWayland is true.
+	// Path to host wayland socket.
+	//
+	// Populated during toSystem if DirectWayland is true.
 	SocketPath *check.Absolute
 }
 

internal/outcome/spx11.go

@@ -50,7 +50,10 @@ func (s *spX11Op) toSystem(state *outcomeStateSys) error {
 	if socketPath != nil {
 		if _, err := state.k.stat(socketPath.String()); err != nil {
 			if !errors.Is(err, fs.ErrNotExist) {
-				return &hst.AppError{Step: fmt.Sprintf("access X11 socket %q", socketPath), Err: err}
+				return &hst.AppError{Step: fmt.Sprintf(
+					"access X11 socket %q",
+					socketPath,
+				), Err: err}
 			}
 		} else {
 			state.sys.UpdatePermType(hst.EX11, socketPath, acl.Read, acl.Write, acl.Execute)

internal/pkg/exec.go

@@ -23,7 +23,7 @@ import (
 	"hakurei.app/message"
 )
 
-// AbsWork is the container pathname [CureContext.GetWorkDir] is mounted on.
+// AbsWork is the container pathname [TContext.GetWorkDir] is mounted on.
 var AbsWork = fhs.AbsRoot.Append("work/")
 
 // ExecPath is a slice of [Artifact] and the [check.Absolute] pathname to make
@@ -39,22 +39,23 @@ type ExecPath struct {
 	W bool
 }
 
-// layers returns pathnames collected from A deduplicated by checksum.
-func (p *ExecPath) layers(f *FContext) []*check.Absolute {
-	msg := f.GetMessage()
+// SetSchedIdle is whether to set [std.SCHED_IDLE] scheduling priority.
+var SetSchedIdle bool
 
-	layers := make([]*check.Absolute, 0, len(p.A))
-	checksums := make(map[unique.Handle[Checksum]]struct{}, len(p.A))
-	for i := range p.A {
-		d := p.A[len(p.A)-1-i]
-		pathname, checksum := f.GetArtifact(d)
+// PromoteLayers returns artifacts with identical-by-content layers promoted to
+// the highest priority instance, as if mounted via [ExecPath].
+func PromoteLayers(
+	artifacts []Artifact,
+	getArtifact func(Artifact) (*check.Absolute, unique.Handle[Checksum]),
+	report func(i int, d Artifact),
+) []*check.Absolute {
+	layers := make([]*check.Absolute, 0, len(artifacts))
+	checksums := make(map[unique.Handle[Checksum]]struct{}, len(artifacts))
+	for i := range artifacts {
+		d := artifacts[len(artifacts)-1-i]
+		pathname, checksum := getArtifact(d)
 		if _, ok := checksums[checksum]; ok {
-			if msg.IsVerbose() {
-				msg.Verbosef(
-					"promoted layer %d as %s",
-					len(p.A)-1-i, reportName(d, f.cache.Ident(d)),
-				)
-			}
+			report(len(artifacts)-1-i, d)
 			continue
 		}
 		checksums[checksum] = struct{}{}
@@ -64,6 +65,19 @@ func (p *ExecPath) layers(f *FContext) []*check.Absolute {
 	return layers
 }
 
+// layers returns pathnames collected from A deduplicated via [PromoteLayers].
+func (p *ExecPath) layers(f *FContext) []*check.Absolute {
+	msg := f.GetMessage()
+	return PromoteLayers(p.A, f.GetArtifact, func(i int, d Artifact) {
+		if msg.IsVerbose() {
+			msg.Verbosef(
+				"promoted layer %d as %s",
+				i, reportName(d, f.cache.Ident(d)),
+			)
+		}
+	})
+}
+
 // Path returns a populated [ExecPath].
 func Path(pathname *check.Absolute, writable bool, a ...Artifact) ExecPath {
 	return ExecPath{pathname, a, writable}
@@ -347,6 +361,7 @@ const (
 // scanVerbose prefixes program output for a verbose [message.Msg].
 func scanVerbose(
 	msg message.Msg,
+	cancel context.CancelFunc,
 	done chan<- struct{},
 	prefix string,
 	r io.Reader,
@@ -361,10 +376,15 @@ func scanVerbose(
 		msg.Verbose(prefix, s.Text())
 	}
 	if err := s.Err(); err != nil && !errors.Is(err, os.ErrClosed) {
+		cancel()
 		msg.Verbose("*"+prefix, err)
 	}
 }
 
+// SeccompPresets is the [seccomp] presets used by exec artifacts.
+const SeccompPresets = std.PresetStrict &
+	^(std.PresetDenyNS | std.PresetDenyDevel)
+
 // cure is like Cure but allows optional host net namespace. This is used for
 // the [KnownChecksum] variant where networking is allowed.
 func (a *execArtifact) cure(f *FContext, hostNet bool) (err error) {
@@ -388,15 +408,23 @@ func (a *execArtifact) cure(f *FContext, hostNet bool) (err error) {
 
 	z := container.New(ctx, f.GetMessage())
 	z.WaitDelay = execWaitDelay
-	z.SeccompPresets |= std.PresetStrict & ^std.PresetDenyNS
+	z.SeccompPresets = SeccompPresets
 	z.SeccompFlags |= seccomp.AllowMultiarch
 	z.ParentPerm = 0700
 	z.HostNet = hostNet
 	z.Hostname = "cure"
+	z.SetScheduler = SetSchedIdle
+	z.SchedPolicy = std.SCHED_IDLE
 	if z.HostNet {
 		z.Hostname = "cure-net"
 	}
 	z.Uid, z.Gid = (1<<10)-1, (1<<10)-1
+
+	var status io.Writer
+	if status, err = f.GetStatusWriter(); err != nil {
+		return
+	}
+
 	if msg := f.GetMessage(); msg.IsVerbose() {
 		var stdout, stderr io.ReadCloser
 		if stdout, err = z.StdoutPipe(); err != nil {
@@ -413,10 +441,26 @@ func (a *execArtifact) cure(f *FContext, hostNet bool) (err error) {
 			}
 		}()
 
+		brStdout, brStderr := f.cache.getReader(stdout), f.cache.getReader(stderr)
 		stdoutDone, stderrDone := make(chan struct{}), make(chan struct{})
-		go scanVerbose(msg, stdoutDone, "("+a.name+":1)", stdout)
-		go scanVerbose(msg, stderrDone, "("+a.name+":2)", stderr)
-		defer func() { <-stdoutDone; <-stderrDone }()
+		go scanVerbose(
+			msg, cancel, stdoutDone,
+			"("+a.name+":1)",
+			io.TeeReader(brStdout, status),
+		)
+		go scanVerbose(
+			msg, cancel, stderrDone,
+			"("+a.name+":2)",
+			io.TeeReader(brStderr, status),
+		)
+		defer func() {
+			<-stdoutDone
+			<-stderrDone
+			f.cache.putReader(brStdout)
+			f.cache.putReader(brStderr)
+		}()
+	} else {
+		z.Stdout, z.Stderr = status, status
 	}
 
 	z.Dir, z.Env, z.Path, z.Args = a.dir, a.env, a.path, a.args

internal/pkg/ir.go

@@ -150,7 +150,7 @@ func (i *IContext) WriteUint32(v uint32) {
 }
 
 // irMaxStringLength is the maximum acceptable wire size of [IRKindString].
-const irMaxStringLength = 1 << 20
+const irMaxStringLength = 1 << 24
 
 // IRStringError is a string value too big to encode in IR.
 type IRStringError string
@@ -310,6 +310,13 @@ type (
 	// verbose logging is enabled. Artifacts may only depend on artifacts
 	// previously described in the IR stream.
 	//
+	// IRDecoder rejects an IR stream on the first decoding error, it does not
+	// check against nonzero reserved ancillary data or incorrectly ordered or
+	// redundant unstructured dependencies. An invalid IR stream as such will
+	// yield [Artifact] values with identifiers disagreeing with those computed
+	// by IRDecoder. For this reason, IRDecoder does not access the ident cache
+	// to avoid putting [Cache] into an inconsistent state.
+	//
 	// Methods of IRDecoder are not safe for concurrent use.
 	IRDecoder struct {
 		// Address of underlying [Cache], must not be exposed directly.

internal/pkg/pkg.go

@@ -28,15 +28,21 @@ import (
 	"unsafe"
 
 	"hakurei.app/container/check"
+	"hakurei.app/internal/info"
 	"hakurei.app/internal/lockedfile"
 	"hakurei.app/message"
 )
 
+const (
+	// programName is the string identifying this build system.
+	programName = "internal/pkg"
+)
+
 type (
 	// A Checksum is a SHA-384 checksum computed for a cured [Artifact].
 	Checksum = [sha512.Size384]byte
 
-	// An ID is a unique identifier returned by [Artifact.ID]. This value must
+	// An ID is a unique identifier returned by [KnownIdent.ID]. This value must
 	// be deterministically determined ahead of time.
 	ID Checksum
 )
@@ -65,18 +71,75 @@ func MustDecode(s string) (checksum Checksum) {
 	return
 }
 
+// common holds elements and receives methods shared between different contexts.
+type common struct {
+	// Address of underlying [Cache], should be zeroed or made unusable after
+	// Cure returns and must not be exposed directly.
+	cache *Cache
+}
+
 // TContext is passed to [TrivialArtifact.Cure] and provides information and
 // methods required for curing the [TrivialArtifact].
 //
 // Methods of TContext are safe for concurrent use. TContext is valid
 // until [TrivialArtifact.Cure] returns.
 type TContext struct {
-	// Address of underlying [Cache], should be zeroed or made unusable after
-	// [TrivialArtifact.Cure] returns and must not be exposed directly.
-	cache *Cache
-
 	// Populated during [Cache.Cure].
 	work, temp *check.Absolute
+
+	// Target [Artifact] encoded identifier.
+	ids string
+	// Pathname status was created at.
+	statusPath *check.Absolute
+	// File statusHeader and logs are written to.
+	status *os.File
+	// Error value during prepareStatus.
+	statusErr error
+
+	common
+}
+
+// statusHeader is the header written to all status files in dirStatus.
+var statusHeader = func() string {
+	s := programName
+	if v := info.Version(); v != info.FallbackVersion {
+		s += " " + v
+	}
+	s += " (" + runtime.GOARCH + ")"
+	if name, err := os.Hostname(); err == nil {
+		s += " on " + name
+	}
+	s += "\n\n"
+	return s
+}()
+
+// prepareStatus initialises the status file once.
+func (t *TContext) prepareStatus() error {
+	if t.statusPath != nil || t.status != nil {
+		return t.statusErr
+	}
+
+	t.statusPath = t.cache.base.Append(
+		dirStatus,
+		t.ids,
+	)
+	if t.status, t.statusErr = os.OpenFile(
+		t.statusPath.String(),
+		syscall.O_CREAT|syscall.O_EXCL|syscall.O_WRONLY,
+		0400,
+	); t.statusErr != nil {
+		return t.statusErr
+	}
+
+	_, t.statusErr = t.status.WriteString(statusHeader)
+	return t.statusErr
+}
+
+// GetStatusWriter returns a [io.Writer] for build logs. The caller must not
+// seek this writer before the position it was first returned in.
+func (t *TContext) GetStatusWriter() (io.Writer, error) {
+	err := t.prepareStatus()
+	return t.status, err
 }
 
 // destroy destroys the temporary directory and joins its errors with the error
@@ -84,12 +147,15 @@ type TContext struct {
 // directory is removed similarly. [Cache] is responsible for making sure work
 // is never left behind for a successful [Cache.Cure].
 //
+// If implementation had requested status, it is closed with error joined with
+// the error referred to by errP. If the error referred to by errP is non-nil,
+// the status file is removed from the filesystem.
+//
 // destroy must be deferred by [Cache.Cure] if [TContext] is passed to any Cure
 // implementation. It should not be called prior to that point.
 func (t *TContext) destroy(errP *error) {
 	if chmodErr, removeErr := removeAll(t.temp); chmodErr != nil || removeErr != nil {
 		*errP = errors.Join(*errP, chmodErr, removeErr)
-		return
 	}
 
 	if *errP != nil {
@@ -97,17 +163,31 @@ func (t *TContext) destroy(errP *error) {
 		if chmodErr != nil || removeErr != nil {
 			*errP = errors.Join(*errP, chmodErr, removeErr)
 		} else if errors.Is(*errP, os.ErrExist) {
-			// two artifacts may be backed by the same file
-			*errP = nil
+			var linkError *os.LinkError
+			if errors.As(*errP, &linkError) && linkError != nil &&
+				linkError.Op == "rename" {
+				// two artifacts may be backed by the same file
+				*errP = nil
+			}
 		}
 	}
+
+	if t.status != nil {
+		if err := t.status.Close(); err != nil {
+			*errP = errors.Join(*errP, err)
+		}
+		if *errP != nil {
+			*errP = errors.Join(*errP, os.Remove(t.statusPath.String()))
+		}
+		t.status = nil
+	}
 }
 
 // Unwrap returns the underlying [context.Context].
-func (t *TContext) Unwrap() context.Context { return t.cache.ctx }
+func (c *common) Unwrap() context.Context { return c.cache.ctx }
 
 // GetMessage returns [message.Msg] held by the underlying [Cache].
-func (t *TContext) GetMessage() message.Msg { return t.cache.msg }
+func (c *common) GetMessage() message.Msg { return c.cache.msg }
 
 // GetWorkDir returns a pathname to a directory which [Artifact] is expected to
 // write its output to. This is not the final resting place of the [Artifact]
@@ -126,13 +206,13 @@ func (t *TContext) GetTempDir() *check.Absolute { return t.temp }
 // If err is nil, the caller must close the resulting [io.ReadCloser] and return
 // its error, if any. Failure to read r to EOF may result in a spurious
 // [ChecksumMismatchError], or the underlying implementation may block on Close.
-func (t *TContext) Open(a Artifact) (r io.ReadCloser, err error) {
+func (c *common) Open(a Artifact) (r io.ReadCloser, err error) {
 	if f, ok := a.(FileArtifact); ok {
-		return t.cache.openFile(f)
+		return c.cache.openFile(f)
 	}
 
 	var pathname *check.Absolute
-	if pathname, _, err = t.cache.Cure(a); err != nil {
+	if pathname, _, err = c.cache.Cure(a); err != nil {
 		return
 	}
 
@@ -164,7 +244,7 @@ type FContext struct {
 }
 
 // InvalidLookupError is the identifier of non-dependency [Artifact] looked up
-// via [FContext.Pathname] by a misbehaving [Artifact] implementation.
+// via [FContext.GetArtifact] by a misbehaving [Artifact] implementation.
 type InvalidLookupError ID
 
 func (e InvalidLookupError) Error() string {
@@ -191,14 +271,7 @@ func (f *FContext) GetArtifact(a Artifact) (
 //
 // Methods of RContext are safe for concurrent use. RContext is valid
 // until [FileArtifact.Cure] returns.
-type RContext struct {
-	// Address of underlying [Cache], should be zeroed or made unusable after
-	// [FileArtifact.Cure] returns and must not be exposed directly.
-	cache *Cache
-}
-
-// Unwrap returns the underlying [context.Context].
-func (r *RContext) Unwrap() context.Context { return r.cache.ctx }
+type RContext struct{ common }
 
 // An Artifact is a read-only reference to a piece of data that may be created
 // deterministically but might not currently be available in memory or on the
@@ -377,6 +450,9 @@ const (
 	// dirChecksum is the directory name appended to Cache.base for storing
 	// artifacts named after their [Checksum].
 	dirChecksum = "checksum"
+	// dirStatus is the directory name appended to Cache.base for storing
+	// artifact metadata and logs named after their [ID].
+	dirStatus = "status"
 
 	// dirWork is the directory name appended to Cache.base for working
 	// pathnames set up during [Cache.Cure].
@@ -466,7 +542,7 @@ type Cache struct {
 	// Synchronises entry into exclusive artifacts for the cure method.
 	exclMu sync.Mutex
 	// Buffered I/O free list, must not be accessed directly.
-	bufioPool sync.Pool
+	brPool, bwPool sync.Pool
 
 	// Unlocks the on-filesystem cache. Must only be called from Close.
 	unlock func()
@@ -548,6 +624,26 @@ func (c *Cache) unsafeIdent(a Artifact, encodeKind bool) (
 	return
 }
 
+// getReader is like [bufio.NewReader] but for brPool.
+func (c *Cache) getReader(r io.Reader) *bufio.Reader {
+	br := c.brPool.Get().(*bufio.Reader)
+	br.Reset(r)
+	return br
+}
+
+// putReader adds br to brPool.
+func (c *Cache) putReader(br *bufio.Reader) { c.brPool.Put(br) }
+
+// getWriter is like [bufio.NewWriter] but for bwPool.
+func (c *Cache) getWriter(w io.Writer) *bufio.Writer {
+	bw := c.bwPool.Get().(*bufio.Writer)
+	bw.Reset(w)
+	return bw
+}
+
+// putWriter adds bw to bwPool.
+func (c *Cache) putWriter(bw *bufio.Writer) { c.bwPool.Put(bw) }
+
 // A ChecksumMismatchError describes an [Artifact] with unexpected content.
 type ChecksumMismatchError struct {
 	// Actual and expected checksums.
@@ -569,6 +665,9 @@ type ScrubError struct {
 	// Dangling identifier symlinks. This can happen if the content-addressed
 	// entry was removed while scrubbing due to a checksum mismatch.
 	DanglingIdentifiers []ID
+	// Dangling status files. This can happen if a dangling status symlink was
+	// removed while scrubbing.
+	DanglingStatus []ID
 	// Miscellaneous errors, including [os.ReadDir] on checksum and identifier
 	// directories, [Decode] on entry names and [os.RemoveAll] on inconsistent
 	// entries.
@@ -620,6 +719,13 @@ func (e *ScrubError) Error() string {
 		}
 		segments = append(segments, s)
 	}
+	if len(e.DanglingStatus) > 0 {
+		s := "dangling status:\n"
+		for _, id := range e.DanglingStatus {
+			s += Encode(id) + "\n"
+		}
+		segments = append(segments, s)
+	}
 	if len(e.Errs) > 0 {
 		s := "errors during scrub:\n"
 		for pathname, errs := range e.errs {
@@ -798,6 +904,36 @@ func (c *Cache) Scrub(checks int) error {
 		wg.Wait()
 	}
 
+	dir = c.base.Append(dirStatus)
+	if entries, readdirErr := os.ReadDir(dir.String()); readdirErr != nil {
+		if !errors.Is(readdirErr, os.ErrNotExist) {
+			addErr(dir, readdirErr)
+		}
+	} else {
+		wg.Add(len(entries))
+		for _, ent := range entries {
+			w <- checkEntry{ent, func(ent os.DirEntry, want *Checksum) bool {
+				got := p.Get().(*Checksum)
+				defer p.Put(got)
+
+				if _, err := os.Stat(c.base.Append(
+					dirIdentifier,
+					ent.Name(),
+				).String()); err != nil {
+					if !errors.Is(err, os.ErrNotExist) {
+						addErr(dir.Append(ent.Name()), err)
+					}
+					seMu.Lock()
+					se.DanglingStatus = append(se.DanglingStatus, *want)
+					seMu.Unlock()
+					return false
+				}
+				return true
+			}}
+		}
+		wg.Wait()
+	}
+
 	if len(c.identPending) > 0 {
 		addErr(c.base, errors.New(
 			"scrub began with pending artifacts",
@@ -828,6 +964,7 @@ func (c *Cache) Scrub(checks int) error {
 
 	if len(se.ChecksumMismatches) > 0 ||
 		len(se.DanglingIdentifiers) > 0 ||
+		len(se.DanglingStatus) > 0 ||
 		len(se.Errs) > 0 {
 		slices.SortFunc(se.ChecksumMismatches, func(a, b ChecksumMismatchError) int {
 			return bytes.Compare(a.Want[:], b.Want[:])
@@ -835,6 +972,9 @@ func (c *Cache) Scrub(checks int) error {
 		slices.SortFunc(se.DanglingIdentifiers, func(a, b ID) int {
 			return bytes.Compare(a[:], b[:])
 		})
+		slices.SortFunc(se.DanglingStatus, func(a, b ID) int {
+			return bytes.Compare(a[:], b[:])
+		})
 		return &se
 	} else {
 		return nil
@@ -925,16 +1065,17 @@ func (c *Cache) openFile(f FileArtifact) (r io.ReadCloser, err error) {
 		if !errors.Is(err, os.ErrNotExist) {
 			return
 		}
+		id := c.Ident(f)
 		if c.msg.IsVerbose() {
-			rn := reportName(f, c.Ident(f))
-			c.msg.Verbosef("curing %s to memory...", rn)
+			rn := reportName(f, id)
+			c.msg.Verbosef("curing %s in memory...", rn)
 			defer func() {
 				if err == nil {
-					c.msg.Verbosef("cured %s to memory", rn)
+					c.msg.Verbosef("opened %s for reading", rn)
 				}
 			}()
 		}
-		return f.Cure(&RContext{c})
+		return f.Cure(&RContext{common{c}})
 	}
 	return
 }
@@ -1131,6 +1272,9 @@ type DependencyCureError []*CureError
 // unwrapM recursively expands underlying errors into a caller-supplied map.
 func (e *DependencyCureError) unwrapM(me map[unique.Handle[ID]]*CureError) {
 	for _, err := range *e {
+		if _, ok := me[err.Ident]; ok {
+			continue
+		}
 		if _e, ok := err.Err.(*DependencyCureError); ok {
 			_e.unwrapM(me)
 			continue
@@ -1214,13 +1358,6 @@ func (c *Cache) exitCure(a Artifact, curesExempt bool) {
 	<-c.cures
 }
 
-// getWriter is like [bufio.NewWriter] but for bufioPool.
-func (c *Cache) getWriter(w io.Writer) *bufio.Writer {
-	bw := c.bufioPool.Get().(*bufio.Writer)
-	bw.Reset(w)
-	return bw
-}
-
 // measuredReader implements [io.ReadCloser] and measures the checksum during
 // Close. If the underlying reader is not read to EOF, Close blocks until all
 // remaining data is consumed and validated.
@@ -1303,9 +1440,6 @@ func (r *RContext) NewMeasuredReader(
 	return r.cache.newMeasuredReader(rc, checksum)
 }
 
-// putWriter adds bw to bufioPool.
-func (c *Cache) putWriter(bw *bufio.Writer) { c.bufioPool.Put(bw) }
-
 // cure implements Cure without checking the full dependency graph.
 func (c *Cache) cure(a Artifact, curesExempt bool) (
 	pathname *check.Absolute,
@@ -1437,7 +1571,7 @@ func (c *Cache) cure(a Artifact, curesExempt bool) (
 		if err = c.enterCure(a, curesExempt); err != nil {
 			return
 		}
-		r, err = f.Cure(&RContext{c})
+		r, err = f.Cure(&RContext{common{c}})
 		if err == nil {
 			if checksumPathname == nil || c.IsStrict() {
 				h := sha512.New384()
@@ -1513,7 +1647,12 @@ func (c *Cache) cure(a Artifact, curesExempt bool) (
 		return
 	}
 
-	t := TContext{c, c.base.Append(dirWork, ids), c.base.Append(dirTemp, ids)}
+	t := TContext{
+		c.base.Append(dirWork, ids),
+		c.base.Append(dirTemp, ids),
+		ids, nil, nil, nil,
+		common{c},
+	}
 	switch ca := a.(type) {
 	case TrivialArtifact:
 		defer t.destroy(&err)
@@ -1651,6 +1790,18 @@ func (pending *pendingArtifactDep) cure(c *Cache) {
 	pending.errsMu.Unlock()
 }
 
+// OpenStatus attempts to open the status file associated to an [Artifact]. If
+// err is nil, the caller must close the resulting reader.
+func (c *Cache) OpenStatus(a Artifact) (r io.ReadSeekCloser, err error) {
+	c.identMu.RLock()
+	r, err = os.Open(c.base.Append(
+		dirStatus,
+		Encode(c.Ident(a).Value())).String(),
+	)
+	c.identMu.RUnlock()
+	return
+}
+
 // Close cancels all pending cures and waits for them to clean up.
 func (c *Cache) Close() {
 	c.closeOnce.Do(func() {
@@ -1699,6 +1850,7 @@ func open(
 	for _, name := range []string{
 		dirIdentifier,
 		dirChecksum,
+		dirStatus,
 		dirWork,
 	} {
 		if err := os.MkdirAll(base.Append(name).String(), 0700); err != nil &&
@@ -1713,13 +1865,16 @@ func open(
 		msg:  msg,
 		base: base,
 
+		identPool: sync.Pool{New: func() any { return new(extIdent) }},
+
 		ident:        make(map[unique.Handle[ID]]unique.Handle[Checksum]),
 		identErr:     make(map[unique.Handle[ID]]error),
 		identPending: make(map[unique.Handle[ID]]<-chan struct{}),
+
+		brPool: sync.Pool{New: func() any { return new(bufio.Reader) }},
+		bwPool: sync.Pool{New: func() any { return new(bufio.Writer) }},
 	}
 	c.ctx, c.cancel = context.WithCancel(ctx)
-	c.identPool.New = func() any { return new(extIdent) }
-	c.bufioPool.New = func() any { return new(bufio.Writer) }
 
 	if lock || !testing.Testing() {
 		if unlock, err := lockedfile.MutexAt(

internal/pkg/pkg_test.go

@@ -314,6 +314,11 @@ func checkWithCache(t *testing.T, testCases []cacheTestCase) {
 				t.Fatal(err)
 			}
 
+			// destroy non-deterministic status files
+			if err := os.RemoveAll(base.Append("status").String()); err != nil {
+				t.Fatal(err)
+			}
+
 			var checksum pkg.Checksum
 			if err := pkg.HashDir(&checksum, base); err != nil {
 				t.Fatalf("HashDir: error = %v", err)
@@ -382,6 +387,9 @@ func cureMany(t *testing.T, c *pkg.Cache, steps []cureStep) {
 		} else if step.pathname != ignorePathname && !pathname.Is(step.pathname) {
 			t.Fatalf("Cure: pathname = %q, want %q", pathname, step.pathname)
 		} else if checksum != makeChecksumH(step.checksum) {
+			if checksum == (unique.Handle[pkg.Checksum]{}) {
+				checksum = unique.Make(pkg.Checksum{})
+			}
 			t.Fatalf(
 				"Cure: checksum = %s, want %s",
 				pkg.Encode(checksum.Value()), pkg.Encode(step.checksum),

internal/pkg/tar.go

@@ -10,8 +10,7 @@ import (
 	"io/fs"
 	"net/http"
 	"os"
-
-	"hakurei.app/container/check"
+	"path"
 )
 
 const (
@@ -100,7 +99,6 @@ func (e DisallowedTypeflagError) Error() string {
 
 // Cure cures the [Artifact], producing a directory located at work.
 func (a *tarArtifact) Cure(t *TContext) (err error) {
-	temp := t.GetTempDir()
 	var tr io.ReadCloser
 	if tr, err = t.Open(a.f); err != nil {
 		return
@@ -116,7 +114,9 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 			err = closeErr
 		}
 	}(tr)
-	tr = io.NopCloser(tr)
+	br := t.cache.getReader(tr)
+	defer t.cache.putReader(br)
+	tr = io.NopCloser(br)
 
 	switch a.compression {
 	case TarUncompressed:
@@ -137,14 +137,24 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 	}
 
 	type dirTargetPerm struct {
-		path *check.Absolute
+		path string
 		mode fs.FileMode
 	}
 	var madeDirectories []dirTargetPerm
 
-	if err = os.MkdirAll(temp.String(), 0700); err != nil {
+	if err = os.MkdirAll(t.GetTempDir().String(), 0700); err != nil {
 		return
 	}
+	var root *os.Root
+	if root, err = os.OpenRoot(t.GetTempDir().String()); err != nil {
+		return
+	}
+	defer func() {
+		closeErr := root.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
 
 	var header *tar.Header
 	r := tar.NewReader(tr)
@@ -158,9 +168,8 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 			}
 		}
 
-		pathname := temp.Append(header.Name)
 		if typeflag >= '0' && typeflag <= '9' && typeflag != tar.TypeDir {
-			if err = os.MkdirAll(pathname.Dir().String(), 0700); err != nil {
+			if err = root.MkdirAll(path.Dir(header.Name), 0700); err != nil {
 				return
 			}
 		}
@@ -168,8 +177,8 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 		switch typeflag {
 		case tar.TypeReg:
 			var f *os.File
-			if f, err = os.OpenFile(
-				pathname.String(),
+			if f, err = root.OpenFile(
+				header.Name,
 				os.O_CREATE|os.O_EXCL|os.O_WRONLY,
 				header.FileInfo().Mode()&0500,
 			); err != nil {
@@ -184,26 +193,29 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 			break
 
 		case tar.TypeLink:
-			if err = os.Link(
-				temp.Append(header.Linkname).String(),
-				pathname.String(),
+			if err = root.Link(
+				header.Linkname,
+				header.Name,
 			); err != nil {
 				return
 			}
 			break
 
 		case tar.TypeSymlink:
-			if err = os.Symlink(header.Linkname, pathname.String()); err != nil {
+			if err = root.Symlink(
+				header.Linkname,
+				header.Name,
+			); err != nil {
 				return
 			}
 			break
 
 		case tar.TypeDir:
 			madeDirectories = append(madeDirectories, dirTargetPerm{
-				path: pathname,
+				path: header.Name,
 				mode: header.FileInfo().Mode(),
 			})
-			if err = os.MkdirAll(pathname.String(), 0700); err != nil {
+			if err = root.MkdirAll(header.Name, 0700); err != nil {
 				return
 			}
 			break
@@ -220,7 +232,7 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 	}
 	if err == nil {
 		for _, e := range madeDirectories {
-			if err = os.Chmod(e.path.String(), e.mode&0500); err != nil {
+			if err = root.Chmod(e.path, e.mode&0500); err != nil {
 				return
 			}
 		}
@@ -228,6 +240,7 @@ func (a *tarArtifact) Cure(t *TContext) (err error) {
 		return
 	}
 
+	temp := t.GetTempDir()
 	if err = os.Chmod(temp.String(), 0700); err != nil {
 		return
 	}

internal/rosa/acl.go

@@ -2,18 +2,19 @@ package rosa
 
 import "hakurei.app/internal/pkg"
 
-func (t Toolchain) newAttr() pkg.Artifact {
+func (t Toolchain) newAttr() (pkg.Artifact, string) {
 	const (
 		version  = "2.5.2"
 		checksum = "YWEphrz6vg1sUMmHHVr1CRo53pFXRhq_pjN-AlG8UgwZK1y6m7zuDhxqJhD0SV0l"
 	)
-	return t.NewViaMake("attr", version, t.NewPatchedSource(
-		"attr", version, pkg.NewHTTPGetTar(
-			nil, "https://download.savannah.nongnu.org/releases/attr/"+
-				"attr-"+version+".tar.gz",
-			mustDecode(checksum),
-			pkg.TarGzip,
-		), true, [2]string{"libgen-basename", `From 8a80d895dfd779373363c3a4b62ecce5a549efb2 Mon Sep 17 00:00:00 2001
+	return t.NewPackage("attr", version, pkg.NewHTTPGetTar(
+		nil, "https://download.savannah.nongnu.org/releases/attr/"+
+			"attr-"+version+".tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	), &PackageAttr{
+		Patches: [][2]string{
+			{"libgen-basename", `From 8a80d895dfd779373363c3a4b62ecce5a549efb2 Mon Sep 17 00:00:00 2001
 From: "Haelwenn (lanodan) Monnier" <contact@hacktivis.me>
 Date: Sat, 30 Mar 2024 10:17:10 +0100
 Subject: tools/attr.c: Add missing libgen.h include for basename(3)
@@ -38,53 +39,72 @@ index f12e4af..6a3c1e9 100644
  #include <attr/attributes.h>
  
 -- 
-cgit v1.1`}, [2]string{"musl-errno", `diff --git a/test/attr.test b/test/attr.test
+cgit v1.1`},
+
+			{"musl-errno", `diff --git a/test/attr.test b/test/attr.test
 index 6ce2f9b..e9bde92 100644
 --- a/test/attr.test
 +++ b/test/attr.test
 @@ -11,7 +11,7 @@ Try various valid and invalid names
-
-        $ touch f
-        $ setfattr -n user -v value f
--       > setfattr: f: Operation not supported
-+       > setfattr: f: Not supported
-
-        $ setfattr -n user. -v value f
-        > setfattr: f: Invalid argument
+ 
+ 	$ touch f
+ 	$ setfattr -n user -v value f
+-	> setfattr: f: Operation not supported
++	> setfattr: f: Not supported
+ 	
+ 	$ setfattr -n user. -v value f
+ 	> setfattr: f: Invalid argument
 `},
-	), &MakeAttr{
+		},
+
 		ScriptEarly: `
 ln -s ../../system/bin/perl /usr/bin
 `,
-		Configure: [][2]string{
-			{"enable-static"},
-		},
-	},
-		t.Load(Perl),
-	)
+	}, (*MakeHelper)(nil),
+		Perl,
+	), version
 }
-func init() { artifactsF[Attr] = Toolchain.newAttr }
+func init() {
+	artifactsM[Attr] = Metadata{
+		f: Toolchain.newAttr,
 
-func (t Toolchain) newACL() pkg.Artifact {
+		Name:        "attr",
+		Description: "Commands for Manipulating Filesystem Extended Attributes",
+		Website:     "https://savannah.nongnu.org/projects/attr/",
+
+		ID: 137,
+	}
+}
+
+func (t Toolchain) newACL() (pkg.Artifact, string) {
 	const (
 		version  = "2.3.2"
 		checksum = "-fY5nwH4K8ZHBCRXrzLdguPkqjKI6WIiGu4dBtrZ1o0t6AIU73w8wwJz_UyjIS0P"
 	)
-	return t.NewViaMake("acl", version, pkg.NewHTTPGetTar(
-		nil,
-		"https://download.savannah.nongnu.org/releases/acl/"+
+	return t.NewPackage("acl", version, pkg.NewHTTPGetTar(
+		nil, "https://download.savannah.nongnu.org/releases/acl/"+
 			"acl-"+version+".tar.gz",
 		mustDecode(checksum),
 		pkg.TarGzip,
-	), &MakeAttr{
-		Configure: [][2]string{
-			{"enable-static"},
-		},
-
+	), nil, &MakeHelper{
 		// makes assumptions about uid_map/gid_map
 		SkipCheck: true,
 	},
-		t.Load(Attr),
-	)
+		Attr,
+	), version
+}
+func init() {
+	artifactsM[ACL] = Metadata{
+		f: Toolchain.newACL,
+
+		Name:        "acl",
+		Description: "Commands for Manipulating POSIX Access Control Lists",
+		Website:     "https://savannah.nongnu.org/projects/acl/",
+
+		Dependencies: P{
+			Attr,
+		},
+
+		ID: 16,
+	}
 }
-func init() { artifactsF[ACL] = Toolchain.newACL }

internal/rosa/all.go

@@ -1,6 +1,12 @@
 package rosa
 
 import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"strconv"
 	"sync"
 
 	"hakurei.app/internal/pkg"
@@ -10,20 +16,50 @@ import (
 type PArtifact int
 
 const (
-	ACL PArtifact = iota
+	LLVMCompilerRT PArtifact = iota
+	LLVMRuntimes
+	LLVMClang
+
+	// EarlyInit is the Rosa OS init program.
+	EarlyInit
+	// ImageSystem is the Rosa OS /system image.
+	ImageSystem
+	// ImageInitramfs is the Rosa OS initramfs archive.
+	ImageInitramfs
+
+	// Kernel is the generic Rosa OS Linux kernel.
+	Kernel
+	// KernelHeaders is an installation of kernel headers for [Kernel].
+	KernelHeaders
+	// KernelSource is a writable kernel source tree installed to [AbsUsrSrc].
+	KernelSource
+	// Firmware is firmware blobs for use with the Linux kernel.
+	Firmware
+
+	ACL
+	ArgpStandalone
 	Attr
 	Autoconf
 	Automake
+	BC
 	Bash
 	Binutils
+	Bison
+	Bzip2
 	CMake
 	Coreutils
 	Curl
+	DTC
 	Diffutils
+	Elfutils
+	Fakeroot
 	Findutils
+	Flex
 	Fuse
-	Gawk
 	GMP
+	GLib
+	Gawk
+	GenInitCPIO
 	Gettext
 	Git
 	Go
@@ -32,10 +68,11 @@ const (
 	Gzip
 	Hakurei
 	HakureiDist
-	IniConfig
-	KernelHeaders
+	Kmod
 	LibXau
+	Libcap
 	Libexpat
+	Libiconv
 	Libpsl
 	Libffi
 	Libgd
@@ -43,31 +80,66 @@ const (
 	Libseccomp
 	Libucontext
 	Libxml2
+	Libxslt
 	M4
 	MPC
 	MPFR
 	Make
 	Meson
 	Mksh
+	MuslFts
+	MuslObstack
 	NSS
 	NSSCACert
+	Ncurses
+	Nettle
 	Ninja
 	OpenSSL
-	Packaging
+	PCRE2
+	Parallel
 	Patch
 	Perl
+	PerlLocaleGettext
+	PerlMIMECharset
+	PerlModuleBuild
+	PerlPodParser
+	PerlSGMLS
+	PerlTermReadKey
+	PerlTextCharWidth
+	PerlTextWrapI18N
+	PerlUnicodeGCString
+	PerlYAMLTiny
 	PkgConfig
-	Pluggy
-	PyTest
-	Pygments
+	Procps
 	Python
+	PythonCfgv
+	PythonDiscovery
+	PythonDistlib
+	PythonFilelock
+	PythonIdentify
+	PythonIniConfig
+	PythonNodeenv
+	PythonPackaging
+	PythonPlatformdirs
+	PythonPluggy
+	PythonPreCommit
+	PythonPyTest
+	PythonPyYAML
+	PythonPygments
+	PythonVirtualenv
+	QEMU
+	Rdfind
 	Rsync
 	Sed
 	Setuptools
+	SquashfsTools
+	TamaGo
+	Tar
+	Texinfo
 	Toybox
 	toyboxEarly
 	Unzip
-	utilMacros
+	UtilLinux
 	Wayland
 	WaylandProtocols
 	XCB
@@ -75,101 +147,187 @@ const (
 	Xproto
 	XZ
 	Zlib
+	Zstd
 
-	buildcatrust
+	// PresetUnexportedStart is the first unexported preset.
+	PresetUnexportedStart
+
+	buildcatrust = iota - 1
+	utilMacros
+
+	// Musl is a standalone libc that does not depend on the toolchain.
+	Musl
 
 	// gcc is a hacked-to-pieces GCC toolchain meant for use in intermediate
 	// stages only. This preset and its direct output must never be exposed.
 	gcc
 
-	// _presetEnd is the total number of presets and does not denote a preset.
-	_presetEnd
+	// Stage0 is a tarball containing all compile-time dependencies of artifacts
+	// part of the [Std] toolchain.
+	Stage0
+
+	// PresetEnd is the total number of presets and does not denote a preset.
+	PresetEnd
 )
 
+// P represents multiple [PArtifact] and is stable through JSON.
+type P []PArtifact
+
+// MarshalJSON represents [PArtifact] by their [Metadata.Name].
+func (s P) MarshalJSON() ([]byte, error) {
+	names := make([]string, len(s))
+	for i, p := range s {
+		names[i] = GetMetadata(p).Name
+	}
+	return json.Marshal(names)
+}
+
+// UnmarshalJSON resolves the value created by MarshalJSON back to [P].
+func (s *P) UnmarshalJSON(data []byte) error {
+	var names []string
+	if err := json.Unmarshal(data, &names); err != nil {
+		return err
+	}
+
+	*s = make(P, len(names))
+	for i, name := range names {
+		if p, ok := ResolveName(name); !ok {
+			return fmt.Errorf("unknown artifact %q", name)
+		} else {
+			(*s)[i] = p
+		}
+	}
+	return nil
+}
+
+// Metadata is stage-agnostic information of a [PArtifact] not directly
+// representable in the resulting [pkg.Artifact].
+type Metadata struct {
+	f func(t Toolchain) (a pkg.Artifact, version string)
+
+	// Unique package name.
+	Name string `json:"name"`
+	// Short user-facing description.
+	Description string `json:"description"`
+	// Project home page.
+	Website string `json:"website,omitempty"`
+
+	// Runtime dependencies.
+	Dependencies P `json:"dependencies"`
+
+	// Project identifier on [Anitya].
+	//
+	// [Anitya]: https://release-monitoring.org/
+	ID int `json:"-"`
+
+	// Optional custom version checking behaviour.
+	latest func(v *Versions) string
+}
+
+// GetLatest returns the latest version described by v.
+func (meta *Metadata) GetLatest(v *Versions) string {
+	if meta.latest != nil {
+		return meta.latest(v)
+	}
+	return v.Latest
+}
+
+// Unversioned denotes an unversioned [PArtifact].
+const Unversioned = "\x00"
+
+// UnpopulatedIDError is returned by [Metadata.GetLatest] for an instance of
+// [Metadata] where ID is not populated.
+type UnpopulatedIDError struct{}
+
+func (UnpopulatedIDError) Unwrap() error { return errors.ErrUnsupported }
+func (UnpopulatedIDError) Error() string { return "Anitya ID is not populated" }
+
+// Versions are package versions returned by Anitya.
+type Versions struct {
+	// The latest version for the project, as determined by the version sorting algorithm.
+	Latest string `json:"latest_version"`
+	// List of all versions that aren’t flagged as pre-release.
+	Stable []string `json:"stable_versions"`
+	// List of all versions stored, sorted from newest to oldest.
+	All []string `json:"versions"`
+}
+
+// getStable returns the first Stable version, or Latest if that is unavailable.
+func (v *Versions) getStable() string {
+	if len(v.Stable) == 0 {
+		return v.Latest
+	}
+	return v.Stable[0]
+}
+
+// GetVersions returns versions fetched from Anitya.
+func (meta *Metadata) GetVersions(ctx context.Context) (*Versions, error) {
+	if meta.ID == 0 {
+		return nil, UnpopulatedIDError{}
+	}
+
+	var resp *http.Response
+	if req, err := http.NewRequestWithContext(
+		ctx,
+		http.MethodGet,
+		"https://release-monitoring.org/api/v2/versions/?project_id="+
+			strconv.Itoa(meta.ID),
+		nil,
+	); err != nil {
+		return nil, err
+	} else {
+		req.Header.Set("User-Agent", "Rosa/1.1")
+		if resp, err = http.DefaultClient.Do(req); err != nil {
+			return nil, err
+		}
+	}
+
+	var v Versions
+	err := json.NewDecoder(resp.Body).Decode(&v)
+	return &v, errors.Join(err, resp.Body.Close())
+}
+
 var (
-	// artifactsF is an array of functions for the result of [PArtifact].
-	artifactsF [_presetEnd]func(t Toolchain) pkg.Artifact
+	// artifactsM is an array of [PArtifact] metadata.
+	artifactsM [PresetEnd]Metadata
 
-	// artifacts stores the result of artifactsF.
-	artifacts [_toolchainEnd][len(artifactsF)]pkg.Artifact
+	// artifacts stores the result of Metadata.f.
+	artifacts [_toolchainEnd][len(artifactsM)]struct {
+		a pkg.Artifact
+		v string
+	}
 	// artifactsOnce is for lazy initialisation of artifacts.
-	artifactsOnce [_toolchainEnd][len(artifactsF)]sync.Once
+	artifactsOnce [_toolchainEnd][len(artifactsM)]sync.Once
 )
 
+// GetMetadata returns [Metadata] of a [PArtifact].
+func GetMetadata(p PArtifact) *Metadata { return &artifactsM[p] }
+
+// construct constructs a [pkg.Artifact] corresponding to a [PArtifact] once.
+func (t Toolchain) construct(p PArtifact) {
+	artifactsOnce[t][p].Do(func() {
+		artifacts[t][p].a, artifacts[t][p].v = artifactsM[p].f(t)
+	})
+}
+
 // Load returns the resulting [pkg.Artifact] of [PArtifact].
 func (t Toolchain) Load(p PArtifact) pkg.Artifact {
-	artifactsOnce[t][p].Do(func() {
-		artifacts[t][p] = artifactsF[p](t)
-	})
-	return artifacts[t][p]
+	t.construct(p)
+	return artifacts[t][p].a
+}
+
+// Version returns the version string of [PArtifact].
+func (t Toolchain) Version(p PArtifact) string {
+	t.construct(p)
+	return artifacts[t][p].v
 }
 
 // ResolveName returns a [PArtifact] by name.
 func ResolveName(name string) (p PArtifact, ok bool) {
-	p, ok = map[string]PArtifact{
-		"acl":               ACL,
-		"attr":              Attr,
-		"autoconf":          Autoconf,
-		"automake":          Automake,
-		"bash":              Bash,
-		"binutils":          Binutils,
-		"cmake":             CMake,
-		"coreutils":         Coreutils,
-		"curl":              Curl,
-		"diffutils":         Diffutils,
-		"findutils":         Findutils,
-		"fuse":              Fuse,
-		"gawk":              Gawk,
-		"gmp":               GMP,
-		"gettext":           Gettext,
-		"git":               Git,
-		"go":                Go,
-		"gperf":             Gperf,
-		"grep":              Grep,
-		"gzip":              Gzip,
-		"hakurei":           Hakurei,
-		"hakurei-dist":      HakureiDist,
-		"iniconfig":         IniConfig,
-		"kernel-headers":    KernelHeaders,
-		"libXau":            LibXau,
-		"libexpat":          Libexpat,
-		"libpsl":            Libpsl,
-		"libseccomp":        Libseccomp,
-		"libucontext":       Libucontext,
-		"libxml2":           Libxml2,
-		"libffi":            Libffi,
-		"libgd":             Libgd,
-		"libtool":           Libtool,
-		"m4":                M4,
-		"mpc":               MPC,
-		"mpfr":              MPFR,
-		"make":              Make,
-		"meson":             Meson,
-		"mksh":              Mksh,
-		"nss":               NSS,
-		"nss-cacert":        NSSCACert,
-		"ninja":             Ninja,
-		"openssl":           OpenSSL,
-		"packaging":         Packaging,
-		"patch":             Patch,
-		"perl":              Perl,
-		"pkg-config":        PkgConfig,
-		"pluggy":            Pluggy,
-		"pytest":            PyTest,
-		"pygments":          Pygments,
-		"python":            Python,
-		"rsync":             Rsync,
-		"sed":               Sed,
-		"setuptools":        Setuptools,
-		"toybox":            Toybox,
-		"unzip":             Unzip,
-		"wayland":           Wayland,
-		"wayland-protocols": WaylandProtocols,
-		"xcb":               XCB,
-		"xcb-proto":         XCBProto,
-		"xproto":            Xproto,
-		"xz":                XZ,
-		"zlib":              Zlib,
-	}[name]
-	return
+	for i := range PresetUnexportedStart {
+		if name == artifactsM[i].Name {
+			return i, true
+		}
+	}
+	return 0, false
 }

internal/rosa/all_test.go

@@ -0,0 +1,66 @@
+package rosa_test
+
+import (
+	"testing"
+
+	"hakurei.app/internal/rosa"
+)
+
+func TestLoad(t *testing.T) {
+	t.Parallel()
+
+	for i := range rosa.PresetEnd {
+		p := rosa.PArtifact(i)
+		t.Run(rosa.GetMetadata(p).Name, func(t *testing.T) {
+			t.Parallel()
+
+			rosa.Std.Load(p)
+		})
+	}
+}
+
+func TestResolveName(t *testing.T) {
+	t.Parallel()
+
+	for i := range rosa.PresetUnexportedStart {
+		p := i
+		name := rosa.GetMetadata(p).Name
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			if got, ok := rosa.ResolveName(name); !ok {
+				t.Fatal("ResolveName: ok = false")
+			} else if got != p {
+				t.Fatalf("ResolveName: %d, want %d", got, p)
+			}
+		})
+	}
+}
+func TestResolveNameUnexported(t *testing.T) {
+	t.Parallel()
+
+	for i := rosa.PresetUnexportedStart; i < rosa.PresetEnd; i++ {
+		p := i
+		name := rosa.GetMetadata(p).Name
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			if got, ok := rosa.ResolveName(name); ok {
+				t.Fatalf("ResolveName: resolved unexported preset %d", got)
+			}
+		})
+	}
+}
+
+func TestUnique(t *testing.T) {
+	t.Parallel()
+
+	names := make(map[string]struct{})
+	for i := range rosa.PresetEnd {
+		name := rosa.GetMetadata(rosa.PArtifact(i)).Name
+		if _, ok := names[name]; ok {
+			t.Fatalf("name %s is not unique", name)
+		}
+		names[name] = struct{}{}
+	}
+}

internal/rosa/argp-standalone.go

@@ -0,0 +1,36 @@
+package rosa
+
+import "hakurei.app/internal/pkg"
+
+func (t Toolchain) newArgpStandalone() (pkg.Artifact, string) {
+	const (
+		version  = "1.3"
+		checksum = "vtW0VyO2pJ-hPyYmDI2zwSLS8QL0sPAUKC1t3zNYbwN2TmsaE-fADhaVtNd3eNFl"
+	)
+	return t.NewPackage("argp-standalone", version, pkg.NewHTTPGetTar(
+		nil, "http://www.lysator.liu.se/~nisse/misc/"+
+			"argp-standalone-"+version+".tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	), &PackageAttr{
+		Env: []string{
+			"CC=cc -std=gnu89 -fPIC",
+		},
+	}, &MakeHelper{
+		Install: `
+install -D -m644 /usr/src/argp-standalone/argp.h /work/system/include/argp.h
+install -D -m755 libargp.a /work/system/lib/libargp.a
+`,
+	},
+		Diffutils,
+	), version
+}
+func init() {
+	artifactsM[ArgpStandalone] = Metadata{
+		f: Toolchain.newArgpStandalone,
+
+		Name:        "argp-standalone",
+		Description: "hierarchical argument parsing library broken out from glibc",
+		Website:     "http://www.lysator.liu.se/~nisse/misc/",
+	}
+}

internal/rosa/bzip2.go

@@ -0,0 +1,38 @@
+package rosa
+
+import "hakurei.app/internal/pkg"
+
+func (t Toolchain) newBzip2() (pkg.Artifact, string) {
+	const (
+		version  = "1.0.8"
+		checksum = "cTLykcco7boom-s05H1JVsQi1AtChYL84nXkg_92Dm1Xt94Ob_qlMg_-NSguIK-c"
+	)
+	return t.NewPackage("bzip2", version, pkg.NewHTTPGetTar(
+		nil, "https://sourceware.org/pub/bzip2/bzip2-"+version+".tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	), &PackageAttr{
+		Writable:    true,
+		EnterSource: true,
+	}, &MakeHelper{
+		// uses source tree as scratch space
+		SkipConfigure: true,
+		SkipCheck:     true,
+		InPlace:       true,
+		Make: []string{
+			"CC=cc",
+		},
+		Install: "make PREFIX=/work/system install",
+	}), version
+}
+func init() {
+	artifactsM[Bzip2] = Metadata{
+		f: Toolchain.newBzip2,
+
+		Name:        "bzip2",
+		Description: "a freely available, patent free, high-quality data compressor",
+		Website:     "https://sourceware.org/bzip2/",
+
+		ID: 237,
+	}
+}

internal/rosa/cmake.go

@@ -1,82 +1,175 @@
 package rosa
 
 import (
+	"path"
 	"slices"
 	"strings"
 
-	"hakurei.app/container/check"
 	"hakurei.app/internal/pkg"
 )
 
-func (t Toolchain) newCMake() pkg.Artifact {
+func (t Toolchain) newCMake() (pkg.Artifact, string) {
 	const (
-		version  = "4.2.1"
-		checksum = "Y3OdbMsob6Xk2y1DCME6z4Fryb5_TkFD7knRT8dTNIRtSqbiCJyyDN9AxggN_I75"
+		version  = "4.2.3"
+		checksum = "Y4uYGnLrDQX78UdzH7fMzfok46Nt_1taDIHSmqgboU1yFi6f0iAXBDegMCu4eS-J"
 	)
-	return t.New("cmake-"+version, 0, []pkg.Artifact{
-		t.Load(Make),
-		t.Load(KernelHeaders),
-	}, nil, nil, `
-cd "$(mktemp -d)"
-/usr/src/cmake/bootstrap \
-	--prefix=/system \
-	--parallel="$(nproc)" \
-	-- \
-	-DCMAKE_USE_OPENSSL=OFF
-make "-j$(nproc)"
-make DESTDIR=/work install
-`, pkg.Path(AbsUsrSrc.Append("cmake"), true, t.NewPatchedSource(
-		// expected to be writable in the copy made during bootstrap
-		"cmake", version, pkg.NewHTTPGetTar(
-			nil, "https://github.com/Kitware/CMake/releases/download/"+
-				"v"+version+"/cmake-"+version+".tar.gz",
-			mustDecode(checksum),
-			pkg.TarGzip,
-		), false,
-	)))
-}
-func init() { artifactsF[CMake] = Toolchain.newCMake }
+	return t.NewPackage("cmake", version, pkg.NewHTTPGetTar(
+		nil, "https://github.com/Kitware/CMake/releases/download/"+
+			"v"+version+"/cmake-"+version+".tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	), &PackageAttr{
+		// test suite expects writable source tree
+		Writable: true,
+
+		// expected to be writable in the copy made during bootstrap
+		Chmod: true,
+
+		Patches: [][2]string{
+			{"bootstrap-test-no-openssl", `diff --git a/Tests/BootstrapTest.cmake b/Tests/BootstrapTest.cmake
+index 137de78bc1..b4da52e664 100644
+--- a/Tests/BootstrapTest.cmake
++++ b/Tests/BootstrapTest.cmake
+@@ -9,7 +9,7 @@ if(NOT nproc EQUAL 0)
+ endif()
+ message(STATUS "running bootstrap: ${bootstrap} ${ninja_arg} ${parallel_arg}")
+ execute_process(
+-  COMMAND ${bootstrap} ${ninja_arg} ${parallel_arg}
++  COMMAND ${bootstrap} ${ninja_arg} ${parallel_arg} -- -DCMAKE_USE_OPENSSL=OFF
+   WORKING_DIRECTORY "${bin_dir}"
+   RESULT_VARIABLE result
+   )
+`},
+
+			{"disable-broken-tests-musl", `diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
+index 2ead810437..f85cbb8b1c 100644
+--- a/Tests/CMakeLists.txt
++++ b/Tests/CMakeLists.txt
+@@ -384,7 +384,6 @@ if(BUILD_TESTING)
+     add_subdirectory(CMakeLib)
+   endif()
+   add_subdirectory(CMakeOnly)
+-  add_subdirectory(RunCMake)
+ 
+   add_subdirectory(FindPackageModeMakefileTest)
+ 
+@@ -528,9 +527,6 @@ if(BUILD_TESTING)
+                                  -DCMake_TEST_CUDA:BOOL=${CMake_TEST_CUDA}
+                                  -DCMake_INSTALL_NAME_TOOL_BUG:BOOL=${CMake_INSTALL_NAME_TOOL_BUG}
+                                  )
+-  ADD_TEST_MACRO(ExportImport ExportImport)
+-  set_property(TEST ExportImport APPEND
+-    PROPERTY LABELS "CUDA")
+   ADD_TEST_MACRO(Unset Unset)
+   ADD_TEST_MACRO(PolicyScope PolicyScope)
+   ADD_TEST_MACRO(EmptyLibrary EmptyLibrary)
+@@ -624,7 +620,6 @@ if(BUILD_TESTING)
+   # run test for BundleUtilities on supported platforms/compilers
+   if((MSVC OR
+       MINGW OR
+-      CMAKE_SYSTEM_NAME MATCHES "Linux" OR
+       CMAKE_SYSTEM_NAME MATCHES "Darwin")
+     AND NOT CMAKE_GENERATOR STREQUAL "Watcom WMake")
+ 
+@@ -3095,10 +3090,6 @@ if(BUILD_TESTING)
+     "${CMake_SOURCE_DIR}/Tests/CTestTestFdSetSize/test.cmake.in"
+     "${CMake_BINARY_DIR}/Tests/CTestTestFdSetSize/test.cmake"
+     @ONLY ESCAPE_QUOTES)
+-  add_test(CTestTestFdSetSize ${CMAKE_CTEST_COMMAND}
+-    -S "${CMake_BINARY_DIR}/Tests/CTestTestFdSetSize/test.cmake" -j20 -V --timeout 120
+-    --output-log "${CMake_BINARY_DIR}/Tests/CTestTestFdSetSize/testOutput.log"
+-    )
+ 
+   if(CMAKE_TESTS_CDASH_SERVER)
+     set(regex "^([^:]+)://([^/]+)(.*)$")
+`},
+		},
+	}, &MakeHelper{
+		OmitDefaults: true,
+
+		ConfigureName: "/usr/src/cmake/bootstrap",
+		Configure: [][2]string{
+			{"prefix", "/system"},
+			{"parallel", `"$(nproc)"`},
+			{"--"},
+			{"-DCMAKE_USE_OPENSSL", "OFF"},
+			{"-DCMake_TEST_NO_NETWORK", "ON"},
+		},
+		Check: []string{
+			"CTEST_OUTPUT_ON_FAILURE=1",
+			"CTEST_PARALLEL_LEVEL=128",
+			"test",
+		},
+	},
+		KernelHeaders,
+	), version
+}
+func init() {
+	artifactsM[CMake] = Metadata{
+		f: Toolchain.newCMake,
+
+		Name:        "cmake",
+		Description: "cross-platform, open-source build system",
+		Website:     "https://cmake.org/",
+
+		ID: 306,
+	}
+}
+
+// CMakeHelper is the [CMake] build system helper.
+type CMakeHelper struct {
+	// Joined with name with a dash if non-empty.
+	Variant string
 
-// CMakeAttr holds the project-specific attributes that will be applied to a new
-// [pkg.Artifact] compiled via [CMake].
-type CMakeAttr struct {
 	// Path elements joined with source.
 	Append []string
-	// Use source tree as scratch space.
-	Writable bool
 
 	// CMake CACHE entries.
 	Cache [][2]string
-	// Additional environment variables.
-	Env []string
-	// Runs before cmake.
-	ScriptEarly string
-	// Runs after cmake, replaces default.
-	ScriptConfigured string
 	// Runs after install.
 	Script string
 
-	// Override the default installation prefix [AbsSystem].
-	Prefix *check.Absolute
-
-	// Passed through to [Toolchain.New].
-	Paths []pkg.ExecPath
-	// Passed through to [Toolchain.New].
-	Flag int
+	// Whether to generate Makefile instead.
+	Make bool
 }
 
-// NewViaCMake returns a [pkg.Artifact] for compiling and installing via [CMake].
-func (t Toolchain) NewViaCMake(
-	name, version, variant string,
-	source pkg.Artifact,
-	attr *CMakeAttr,
-	extra ...pkg.Artifact,
-) pkg.Artifact {
-	if name == "" || version == "" || variant == "" {
-		panic("names must be non-empty")
+var _ Helper = new(CMakeHelper)
+
+// name returns its arguments and an optional variant string joined with '-'.
+func (attr *CMakeHelper) name(name, version string) string {
+	if attr != nil && attr.Variant != "" {
+		name += "-" + attr.Variant
 	}
+	return name + "-" + version
+}
+
+// extra returns a hardcoded slice of [CMake] and [Ninja].
+func (attr *CMakeHelper) extra(int) []PArtifact {
+	if attr != nil && attr.Make {
+		return []PArtifact{CMake, Make}
+	}
+	return []PArtifact{CMake, Ninja}
+}
+
+// wantsChmod returns false.
+func (*CMakeHelper) wantsChmod() bool { return false }
+
+// wantsWrite returns false.
+func (*CMakeHelper) wantsWrite() bool { return false }
+
+// scriptEarly returns the zero value.
+func (*CMakeHelper) scriptEarly() string { return "" }
+
+// createDir returns true.
+func (*CMakeHelper) createDir() bool { return true }
+
+// wantsDir returns a hardcoded, deterministic pathname.
+func (*CMakeHelper) wantsDir() string { return "/cure/" }
+
+// script generates the cure script.
+func (attr *CMakeHelper) script(name string) string {
 	if attr == nil {
-		attr = &CMakeAttr{
+		attr = &CMakeHelper{
 			Cache: [][2]string{
 				{"CMAKE_BUILD_TYPE", "Release"},
 			},
@@ -86,40 +179,29 @@ func (t Toolchain) NewViaCMake(
 		panic("CACHE must be non-empty")
 	}
 
-	scriptConfigured := "cmake --build .\ncmake --install .\n"
-	if attr.ScriptConfigured != "" {
-		scriptConfigured = attr.ScriptConfigured
+	generate := "Ninja"
+	jobs := ""
+	if attr.Make {
+		generate = "'Unix Makefiles'"
+		jobs += ` "--parallel=$(nproc)"`
 	}
 
-	prefix := attr.Prefix
-	if prefix == nil {
-		prefix = AbsSystem
-	}
-
-	sourcePath := AbsUsrSrc.Append(name)
-	return t.New(name+"-"+variant+"-"+version, attr.Flag, stage3Concat(t, extra,
-		t.Load(CMake),
-		t.Load(Ninja),
-	), nil, slices.Concat([]string{
-		"ROSA_SOURCE=" + sourcePath.String(),
-		"ROSA_CMAKE_SOURCE=" + sourcePath.Append(attr.Append...).String(),
-		"ROSA_INSTALL_PREFIX=/work" + prefix.String(),
-	}, attr.Env), attr.ScriptEarly+`
-mkdir /cure && cd /cure
-cmake -G Ninja \
+	return `
+cmake -G ` + generate + ` \
 	-DCMAKE_C_COMPILER_TARGET="${ROSA_TRIPLE}" \
 	-DCMAKE_CXX_COMPILER_TARGET="${ROSA_TRIPLE}" \
 	-DCMAKE_ASM_COMPILER_TARGET="${ROSA_TRIPLE}" \
-	`+strings.Join(slices.Collect(func(yield func(string) bool) {
+	-DCMAKE_INSTALL_LIBDIR=lib \
+	` + strings.Join(slices.Collect(func(yield func(string) bool) {
 		for _, v := range attr.Cache {
 			if !yield("-D" + v[0] + "=" + v[1]) {
 				return
 			}
 		}
-	}), " \\\n\t")+` \
-	-DCMAKE_INSTALL_PREFIX="${ROSA_INSTALL_PREFIX}" \
-	"${ROSA_CMAKE_SOURCE}"
-`+scriptConfigured+attr.Script, slices.Concat([]pkg.ExecPath{
-		pkg.Path(sourcePath, attr.Writable, source),
-	}, attr.Paths)...)
+	}), " \\\n\t") + ` \
+	-DCMAKE_INSTALL_PREFIX=/system \
+	'/usr/src/` + name + `/` + path.Join(attr.Append...) + `'
+cmake --build .` + jobs + `
+cmake --install . --prefix=/work/system
+` + attr.Script
 }

internal/rosa/curl.go

@@ -2,31 +2,68 @@ package rosa
 
 import "hakurei.app/internal/pkg"
 
-func (t Toolchain) newCurl() pkg.Artifact {
+func (t Toolchain) newCurl() (pkg.Artifact, string) {
 	const (
-		version  = "8.18.0"
-		checksum = "YpOolP_sx1DIrCEJ3elgVAu0wTLDS-EZMZFvOP0eha7FaLueZUlEpuMwDzJNyi7i"
+		version  = "8.19.0"
+		checksum = "YHuVLVVp8q_Y7-JWpID5ReNjq2Zk6t7ArHB6ngQXilp_R5l3cubdxu3UKo-xDByv"
 	)
-	return t.NewViaMake("curl", version, pkg.NewHTTPGetTar(
+	return t.NewPackage("curl", version, pkg.NewHTTPGetTar(
 		nil, "https://curl.se/download/curl-"+version+".tar.bz2",
 		mustDecode(checksum),
 		pkg.TarBzip2,
-	), &MakeAttr{
-		Env: []string{
-			"TFLAGS=-j256",
+	), &PackageAttr{
+		Patches: [][2]string{
+			{"test459-misplaced-line-break", `diff --git a/tests/data/test459 b/tests/data/test459
+index 7a2e1db7b3..cc716aa65a 100644
+--- a/tests/data/test459
++++ b/tests/data/test459
+@@ -54,8 +54,8 @@ Content-Type: application/x-www-form-urlencoded
+ arg
+ </protocol>
+ <stderr mode="text">
+-Warning: %LOGDIR/config:1 Option 'data' uses argument with unquoted whitespace.%SP
+-Warning: This may cause side-effects. Consider double quotes.
++Warning: %LOGDIR/config:1 Option 'data' uses argument with unquoted%SP
++Warning: whitespace. This may cause side-effects. Consider double quotes.
+ </stderr>
+ </verify>
+ </testcase>
+`},
 		},
+	}, &MakeHelper{
 		Configure: [][2]string{
 			{"with-openssl"},
 			{"with-ca-bundle", "/system/etc/ssl/certs/ca-bundle.crt"},
-		},
-		ScriptConfigured: `
-make "-j$(nproc)"
-`,
-	},
-		t.Load(Perl),
 
-		t.Load(Libpsl),
-		t.Load(OpenSSL),
-	)
+			{"disable-smb"},
+		},
+		Check: []string{
+			`TFLAGS="-j$(expr "$(nproc)" '*' 2)"`,
+			"test-nonflaky",
+		},
+	},
+		Perl,
+		Python,
+		PkgConfig,
+		Diffutils,
+
+		Libpsl,
+		OpenSSL,
+	), version
+}
+func init() {
+	artifactsM[Curl] = Metadata{
+		f: Toolchain.newCurl,
+
+		Name:        "curl",
+		Description: "command line tool and library for transferring data with URLs",
+		Website:     "https://curl.se/",
+
+		Dependencies: P{
+			Libpsl,
+			OpenSSL,
+		},
+
+		ID: 381,
+	}
 }
-func init() { artifactsF[Curl] = Toolchain.newCurl }

internal/rosa/dtc.go

@@ -0,0 +1,43 @@
+package rosa
+
+import "hakurei.app/internal/pkg"
+
+func (t Toolchain) newDTC() (pkg.Artifact, string) {
+	const (
+		version  = "1.7.2"
+		checksum = "vUoiRynPyYRexTpS6USweT5p4SVHvvVJs8uqFkkVD-YnFjwf6v3elQ0-Etrh00Dt"
+	)
+	return t.NewPackage("dtc", version, pkg.NewHTTPGetTar(
+		nil, "https://git.kernel.org/pub/scm/utils/dtc/dtc.git/snapshot/"+
+			"dtc-v"+version+".tar.gz",
+		mustDecode(checksum),
+		pkg.TarGzip,
+	), &PackageAttr{
+		// works around buggy test:
+		// fdtdump-runtest.sh /usr/src/dtc/tests/fdtdump.dts
+		Writable: true,
+		Chmod:    true,
+	}, &MesonHelper{
+		Setup: [][2]string{
+			{"Dyaml", "disabled"},
+			{"Dstatic-build", "true"},
+		},
+	},
+		Flex,
+		Bison,
+		M4,
+		Coreutils,
+		Diffutils,
+	), version
+}
+func init() {
+	artifactsM[DTC] = Metadata{
+		f: Toolchain.newDTC,
+
+		Name:        "dtc",
+		Description: "The Device Tree Compiler",
+		Website:     "https://git.kernel.org/pub/scm/utils/dtc/dtc.git/",
+
+		ID: 16911,
+	}
+}

internal/rosa/elfutils.go

@@ -0,0 +1,59 @@
+package rosa
+
+import "hakurei.app/internal/pkg"
+
+func (t Toolchain) newElfutils() (pkg.Artifact, string) {
+	const (
+		version  = "0.194"
+		checksum = "Q3XUygUPv9vR1TkWucwUsQ8Kb1_F6gzk-KMPELr3cC_4AcTrprhVPMvN0CKkiYRa"
+	)
+	return t.NewPackage("elfutils", version, pkg.NewHTTPGetTar(
+		nil, "https://sourceware.org/elfutils/ftp/"+
+			version+"/elfutils-"+version+".tar.bz2",
+		mustDecode(checksum),
+		pkg.TarBzip2,
+	), &PackageAttr{
+		Env: []string{
+			"CC=cc" +
+				// nonstandard glibc extension
+				" -DFNM_EXTMATCH=0",
+		},
+	}, &MakeHelper{
+		// nonstandard glibc extension
+		SkipCheck: true,
+
+		Configure: [][2]string{
+			{"enable-deterministic-archives"},
+		},
+	},
+		M4,
+		PkgConfig,
+
+		Zlib,
+		Bzip2,
+		Zstd,
+		ArgpStandalone,
+		MuslFts,
+		MuslObstack,
+		KernelHeaders,
+	), version
+}
+func init() {
+	artifactsM[Elfutils] = Metadata{
+		f: Toolchain.newElfutils,
+
+		Name:        "elfutils",
+		Description: "utilities and libraries to handle ELF files and DWARF data",
+		Website:     "https://sourceware.org/elfutils/",
+
+		Dependencies: P{
+			Zlib,
+			Bzip2,
+			Zstd,
+			MuslFts,
+			MuslObstack,
+		},
+
+		ID: 5679,
+	}
+}