container/init: unwrap path errors

These are also now handled by init properly, so wrapping them in self is meaningless and unreachable.

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

container/autoetc.go

@@ -31,10 +31,10 @@ func (e *AutoEtcOp) apply(state *setupState, k syscallDispatcher) error {
 	rel := e.hostRel() + "/"
 
 	if err := k.mkdirAll(target, 0755); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 	if d, err := k.readdir(toSysroot(e.hostPath().String())); err != nil {
-		return wrapErrSelf(err)
+		return err
 	} else {
 		for _, ent := range d {
 			n := ent.Name()
@@ -43,12 +43,12 @@ func (e *AutoEtcOp) apply(state *setupState, k syscallDispatcher) error {
 
 			case "mtab":
 				if err = k.symlink(FHSProc+"mounts", target+n); err != nil {
-					return wrapErrSelf(err)
+					return err
 				}
 
 			default:
 				if err = k.symlink(rel+n, target+n); err != nil {
-					return wrapErrSelf(err)
+					return err
 				}
 			}
 		}

container/autoetc_test.go

@@ -19,14 +19,14 @@ func TestAutoEtcOp(t *testing.T) {
 			Prefix: "81ceabb30d37bbdb3868004629cb84e9",
 		}, nil, nil, []kexpect{
 			{"mkdirAll", expectArgs{"/sysroot/etc/", os.FileMode(0755)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"readdir", new(Params), &AutoEtcOp{
 			Prefix: "81ceabb30d37bbdb3868004629cb84e9",
 		}, nil, nil, []kexpect{
 			{"mkdirAll", expectArgs{"/sysroot/etc/", os.FileMode(0755)}, nil, nil},
 			{"readdir", expectArgs{"/sysroot/etc/.host/81ceabb30d37bbdb3868004629cb84e9"}, stubDir(), errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink", new(Params), &AutoEtcOp{
 			Prefix: "81ceabb30d37bbdb3868004629cb84e9",
@@ -42,7 +42,7 @@ func TestAutoEtcOp(t *testing.T) {
 				"ssh", "ssl", "static", "subgid", "subuid", "sudoers", "sway", "sysctl.d", "systemd", "terminfo",
 				"tmpfiles.d", "udev", "vconsole.conf", "X11", "xdg", "zoneinfo"), nil},
 			{"symlink", expectArgs{".host/81ceabb30d37bbdb3868004629cb84e9/alsa", "/sysroot/etc/alsa"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink mtab", new(Params), &AutoEtcOp{
 			Prefix: "81ceabb30d37bbdb3868004629cb84e9",
@@ -84,7 +84,7 @@ func TestAutoEtcOp(t *testing.T) {
 			{"symlink", expectArgs{".host/81ceabb30d37bbdb3868004629cb84e9/modprobe.d", "/sysroot/etc/modprobe.d"}, nil, nil},
 			{"symlink", expectArgs{".host/81ceabb30d37bbdb3868004629cb84e9/modules-load.d", "/sysroot/etc/modules-load.d"}, nil, nil},
 			{"symlink", expectArgs{"/proc/mounts", "/sysroot/etc/mtab"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"success nested", new(Params), &AutoEtcOp{
 			Prefix: "81ceabb30d37bbdb3868004629cb84e9",

container/autoroot.go

@@ -29,7 +29,7 @@ func (r *AutoRootOp) Valid() bool { return r != nil && r.Host != nil }
 
 func (r *AutoRootOp) early(state *setupState, k syscallDispatcher) error {
 	if d, err := k.readdir(r.Host.String()); err != nil {
-		return wrapErrSelf(err)
+		return err
 	} else {
 		r.resolved = make([]Op, 0, len(d))
 		for _, ent := range d {

container/autoroot_test.go

@@ -20,7 +20,7 @@ func TestAutoRootOp(t *testing.T) {
 			Flags: BindWritable,
 		}, []kexpect{
 			{"readdir", expectArgs{"/"}, stubDir(), errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"early", &Params{ParentPerm: 0750}, &AutoRootOp{
 			Host:  MustAbs("/"),
@@ -29,7 +29,7 @@ func TestAutoRootOp(t *testing.T) {
 			{"readdir", expectArgs{"/"}, stubDir("bin", "dev", "etc", "home", "lib64",
 				"lost+found", "mnt", "nix", "proc", "root", "run", "srv", "sys", "tmp", "usr", "var"), nil},
 			{"evalSymlinks", expectArgs{"/bin"}, "", errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"apply", &Params{ParentPerm: 0750}, &AutoRootOp{
 			Host:  MustAbs("/"),
@@ -51,7 +51,7 @@ func TestAutoRootOp(t *testing.T) {
 		}, nil, []kexpect{
 			{"verbosef", expectArgs{"%s %s", []any{"mounting", &BindMountOp{MustAbs("/usr/bin"), MustAbs("/bin"), MustAbs("/bin"), BindWritable}}}, nil, nil},
 			{"stat", expectArgs{"/host/usr/bin"}, isDirFi(false), errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"success pd", &Params{ParentPerm: 0750}, &AutoRootOp{
 			Host:  MustAbs("/"),

container/init_test.go

@@ -410,13 +410,51 @@ func TestInitEntrypoint(t *testing.T) {
 				{"mount", expectArgs{"", "/", "", uintptr(0x8c000), ""}, nil, nil},
 				/* begin early */
 				{"evalSymlinks", expectArgs{"/"}, "/", errUnique},
-				{"printBaseErr", expectArgs{wrapErrSelf(errUnique), "cannot prepare op at index 0:"}, nil, nil},
+				{"printBaseErr", expectArgs{errUnique, "cannot prepare op at index 0:"}, nil, nil},
 				{"beforeExit", expectArgs{}, nil, nil},
 				{"exit", expectArgs{1}, nil, nil},
 				/* end early */
 			},
 		}, nil},
 
+		{"early", func(k syscallDispatcher) error { initEntrypoint(k, assertPrefix, assertVerboseTrue); return nil }, [][]kexpect{
+			{
+				{"lockOSThread", expectArgs{}, nil, nil},
+				{"getpid", expectArgs{}, 1, nil},
+				{"setPtracer", expectArgs{uintptr(0)}, nil, nil},
+				{"receive", expectArgs{"HAKUREI_SETUP", new(initParams), new(uintptr), &initParams{Params{
+					Dir:            MustAbs("/.hakurei"),
+					Env:            []string{"DISPLAY=:0"},
+					Path:           MustAbs("/bin/zsh"),
+					Args:           []string{"zsh", "-c", "exec vim"},
+					ForwardCancel:  true,
+					AdoptWaitDelay: 5 * time.Second,
+					Uid:            1 << 32,
+					Gid:            1 << 31,
+					Hostname:       "hakurei-check",
+					Ops:            new(Ops).Bind(MustAbs("/"), MustAbs("/"), BindDevice).Proc(MustAbs("/proc/")),
+					SeccompRules:   make([]seccomp.NativeRule, 0),
+					SeccompPresets: seccomp.PresetStrict,
+					RetainSession:  true,
+					Privileged:     true,
+				}, 1000, 100, 3, true}, uintptr(9)}, errUnique, nil},
+				{"verbose", expectArgs{[]any{"received setup parameters"}}, nil, nil},
+				{"setDumpable", expectArgs{uintptr(1)}, nil, nil},
+				{"writeFile", expectArgs{"/proc/self/uid_map", []byte("4294967296 1000 1\n"), os.FileMode(0)}, nil, nil},
+				{"writeFile", expectArgs{"/proc/self/setgroups", []byte("deny\n"), os.FileMode(0)}, nil, nil},
+				{"writeFile", expectArgs{"/proc/self/gid_map", []byte("2147483648 100 1\n"), os.FileMode(0)}, nil, nil},
+				{"setDumpable", expectArgs{uintptr(0)}, nil, nil},
+				{"umask", expectArgs{0}, 022, nil},
+				{"sethostname", expectArgs{[]byte("hakurei-check")}, nil, nil},
+				{"lastcap", expectArgs{}, uintptr(40), nil},
+				{"mount", expectArgs{"", "/", "", uintptr(0x8c000), ""}, nil, nil},
+				/* begin early */
+				{"evalSymlinks", expectArgs{"/"}, "/", &os.PathError{Op: "readlink", Path: "/", Err: errUnique}},
+				{"fatal", expectArgs{[]any{"cannot readlink /: unique error injected by the test suite"}}, nil, nil},
+				/* end early */
+			},
+		}, nil},
+
 		{"mount ih", func(k syscallDispatcher) error { initEntrypoint(k, assertPrefix, assertVerboseTrue); return nil }, [][]kexpect{
 			{
 				{"lockOSThread", expectArgs{}, nil, nil},
@@ -711,6 +749,62 @@ func TestInitEntrypoint(t *testing.T) {
 			},
 		}, nil},
 
+		{"apply unhandled error", func(k syscallDispatcher) error { initEntrypoint(k, assertPrefix, assertVerboseTrue); return nil }, [][]kexpect{
+			{
+				{"lockOSThread", expectArgs{}, nil, nil},
+				{"getpid", expectArgs{}, 1, nil},
+				{"setPtracer", expectArgs{uintptr(0)}, nil, nil},
+				{"receive", expectArgs{"HAKUREI_SETUP", new(initParams), new(uintptr), &initParams{Params{
+					Dir:            MustAbs("/.hakurei"),
+					Env:            []string{"DISPLAY=:0"},
+					Path:           MustAbs("/bin/zsh"),
+					Args:           []string{"zsh", "-c", "exec vim"},
+					ForwardCancel:  true,
+					AdoptWaitDelay: 5 * time.Second,
+					Uid:            1 << 32,
+					Gid:            1 << 31,
+					Hostname:       "hakurei-check",
+					Ops:            new(Ops).Bind(MustAbs("/"), MustAbs("/"), BindDevice).Proc(MustAbs("/proc/")),
+					SeccompRules:   make([]seccomp.NativeRule, 0),
+					SeccompPresets: seccomp.PresetStrict,
+					RetainSession:  true,
+					Privileged:     true,
+				}, 1000, 100, 3, true}, uintptr(9)}, errUnique, nil},
+				{"verbose", expectArgs{[]any{"received setup parameters"}}, nil, nil},
+				{"setDumpable", expectArgs{uintptr(1)}, nil, nil},
+				{"writeFile", expectArgs{"/proc/self/uid_map", []byte("4294967296 1000 1\n"), os.FileMode(0)}, nil, nil},
+				{"writeFile", expectArgs{"/proc/self/setgroups", []byte("deny\n"), os.FileMode(0)}, nil, nil},
+				{"writeFile", expectArgs{"/proc/self/gid_map", []byte("2147483648 100 1\n"), os.FileMode(0)}, nil, nil},
+				{"setDumpable", expectArgs{uintptr(0)}, nil, nil},
+				{"umask", expectArgs{0}, 022, nil},
+				{"sethostname", expectArgs{[]byte("hakurei-check")}, nil, nil},
+				{"lastcap", expectArgs{}, uintptr(40), nil},
+				{"mount", expectArgs{"", "/", "", uintptr(0x8c000), ""}, nil, nil},
+				/* begin early */
+				{"evalSymlinks", expectArgs{"/"}, "/", nil},
+				/* end early */
+				{"mount", expectArgs{"rootfs", "/proc/self/fd", "tmpfs", uintptr(6), ""}, nil, nil},
+				{"chdir", expectArgs{"/proc/self/fd"}, nil, nil},
+				{"mkdir", expectArgs{"sysroot", os.FileMode(0755)}, nil, nil},
+				{"mount", expectArgs{"sysroot", "sysroot", "", uintptr(0xd000), ""}, nil, nil},
+				{"mkdir", expectArgs{"host", os.FileMode(0755)}, nil, nil},
+				{"pivotRoot", expectArgs{"/proc/self/fd", "host"}, nil, nil},
+				{"chdir", expectArgs{"/"}, nil, nil},
+				/* begin apply */
+				{"verbosef", expectArgs{"%s %s", []any{"mounting", &BindMountOp{sourceFinal: MustAbs("/"), Source: MustAbs("/"), Target: MustAbs("/"), Flags: BindDevice}}}, nil, nil},
+				{"stat", expectArgs{"/host"}, isDirFi(true), nil},
+				{"mkdirAll", expectArgs{"/sysroot", os.FileMode(0700)}, nil, nil},
+				{"bindMount", expectArgs{"/host", "/sysroot", uintptr(0x4001), false}, nil, nil},
+				{"verbosef", expectArgs{"%s %s", []any{"mounting", &MountProcOp{Target: MustAbs("/proc/")}}}, nil, nil},
+				{"mkdirAll", expectArgs{"/sysroot/proc", os.FileMode(0755)}, nil, nil},
+				{"mount", expectArgs{"proc", "/sysroot/proc", "proc", uintptr(0xe), ""}, nil, errUnique},
+				{"printBaseErr", expectArgs{errUnique, "cannot apply op at index 1:"}, nil, nil},
+				{"beforeExit", expectArgs{}, nil, nil},
+				{"exit", expectArgs{1}, nil, nil},
+				/* end apply */
+			},
+		}, nil},
+
 		{"apply", func(k syscallDispatcher) error { initEntrypoint(k, assertPrefix, assertVerboseTrue); return nil }, [][]kexpect{
 			{
 				{"lockOSThread", expectArgs{}, nil, nil},

container/initbind.go

@@ -43,7 +43,7 @@ func (b *BindMountOp) Valid() bool {
 func (b *BindMountOp) early(_ *setupState, k syscallDispatcher) error {
 	if b.Flags&BindEnsure != 0 {
 		if err := k.mkdirAll(b.Source.String(), 0700); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 	}
 
@@ -52,7 +52,7 @@ func (b *BindMountOp) early(_ *setupState, k syscallDispatcher) error {
 			// leave sourceFinal as nil
 			return nil
 		}
-		return wrapErrSelf(err)
+		return err
 	} else {
 		b.sourceFinal, err = NewAbs(pathname)
 		return err
@@ -74,10 +74,10 @@ func (b *BindMountOp) apply(_ *setupState, k syscallDispatcher) error {
 	// this perm value emulates bwrap behaviour as it clears bits from 0755 based on
 	// op->perms which is never set for any bind setup op so always results in 0700
 	if fi, err := k.stat(source); err != nil {
-		return wrapErrSelf(err)
+		return err
 	} else if fi.IsDir() {
 		if err = k.mkdirAll(target, 0700); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 	} else if err = k.ensureFile(target, 0444, 0700); err != nil {
 		return err

container/initbind_test.go

@@ -14,7 +14,7 @@ func TestBindMountOp(t *testing.T) {
 			Target: MustAbs("/bin/"),
 		}, []kexpect{
 			{"evalSymlinks", expectArgs{"/bin/"}, "", syscall.ENOENT},
-		}, wrapErrSelf(syscall.ENOENT), nil, nil},
+		}, syscall.ENOENT, nil, nil},
 
 		{"skip optional", new(Params), &BindMountOp{
 			Source: MustAbs("/bin/"),
@@ -53,7 +53,7 @@ func TestBindMountOp(t *testing.T) {
 			Flags:  BindEnsure,
 		}, []kexpect{
 			{"mkdirAll", expectArgs{"/bin/", os.FileMode(0700)}, nil, errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"success ensure", new(Params), &BindMountOp{
 			Source: MustAbs("/bin/"),
@@ -97,7 +97,7 @@ func TestBindMountOp(t *testing.T) {
 			Target: MustAbs("/bin/"),
 		}, []kexpect{
 			{"evalSymlinks", expectArgs{"/bin/"}, "/usr/bin", errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"stat", new(Params), &BindMountOp{
 			Source: MustAbs("/bin/"),
@@ -106,7 +106,7 @@ func TestBindMountOp(t *testing.T) {
 			{"evalSymlinks", expectArgs{"/bin/"}, "/usr/bin", nil},
 		}, nil, []kexpect{
 			{"stat", expectArgs{"/host/usr/bin"}, isDirFi(true), errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mkdirAll", new(Params), &BindMountOp{
 			Source: MustAbs("/bin/"),
@@ -116,7 +116,7 @@ func TestBindMountOp(t *testing.T) {
 		}, nil, []kexpect{
 			{"stat", expectArgs{"/host/usr/bin"}, isDirFi(true), nil},
 			{"mkdirAll", expectArgs{"/sysroot/bin", os.FileMode(0700)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"bindMount", new(Params), &BindMountOp{
 			Source: MustAbs("/bin/"),

container/initdev.go

@@ -59,7 +59,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 			FHSProc+"self/fd/"+string(rune(i+'0')),
 			path.Join(target, name),
 		); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 	}
 	for _, pair := range [][2]string{
@@ -68,7 +68,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 		{"pts/ptmx", "ptmx"},
 	} {
 		if err := k.symlink(pair[0], path.Join(target, pair[1])); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 	}
 
@@ -76,7 +76,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 	devPtsPath := path.Join(target, "pts")
 	for _, name := range []string{devShmPath, devPtsPath} {
 		if err := k.mkdir(name, state.ParentPerm); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 	}
 
@@ -92,7 +92,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 				return err
 			}
 			if name, err := k.readlink(hostProc.stdout()); err != nil {
-				return wrapErrSelf(err)
+				return err
 			} else if err = k.bindMount(
 				toHost(name),
 				consolePath,
@@ -107,7 +107,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 	if d.Mqueue {
 		mqueueTarget := path.Join(target, "mqueue")
 		if err := k.mkdir(mqueueTarget, state.ParentPerm); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 		if err := k.mount(SourceMqueue, mqueueTarget, FstypeMqueue, MS_NOSUID|MS_NOEXEC|MS_NODEV, zeroString); err != nil {
 			return err

container/initdev_test.go

@@ -194,7 +194,7 @@ func TestMountDevOp(t *testing.T) {
 			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
 			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink stdout", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -215,7 +215,7 @@ func TestMountDevOp(t *testing.T) {
 			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink stderr", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -237,7 +237,7 @@ func TestMountDevOp(t *testing.T) {
 			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink fd", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -260,7 +260,7 @@ func TestMountDevOp(t *testing.T) {
 			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink kcore", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -284,7 +284,7 @@ func TestMountDevOp(t *testing.T) {
 			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
 			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
 			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"symlink ptmx", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -309,7 +309,7 @@ func TestMountDevOp(t *testing.T) {
 			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
 			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
 			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mkdir shm", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -335,7 +335,7 @@ func TestMountDevOp(t *testing.T) {
 			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
 			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
 			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mkdir devpts", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -362,7 +362,7 @@ func TestMountDevOp(t *testing.T) {
 			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
 			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
 			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mount devpts", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -451,7 +451,7 @@ func TestMountDevOp(t *testing.T) {
 			{"isatty", expectArgs{1}, true, nil},
 			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
 			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "", errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"bindMount stdout", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -516,7 +516,7 @@ func TestMountDevOp(t *testing.T) {
 			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
 			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
 			{"mkdir", expectArgs{"/sysroot/dev/mqueue", os.FileMode(0750)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mount mqueue", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
@@ -615,6 +615,38 @@ func TestMountDevOp(t *testing.T) {
 			{"mount", expectArgs{"mqueue", "/sysroot/dev/mqueue", "mqueue", uintptr(0xe), ""}, nil, nil},
 		}, nil},
 
+		{"remount", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
+			Target: MustAbs("/dev/"),
+		}, nil, nil, []kexpect{
+			{"mountTmpfs", expectArgs{"devtmpfs", "/sysroot/dev", uintptr(0x6), 0, os.FileMode(0750)}, nil, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/null", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", expectArgs{"/host/dev/null", "/sysroot/dev/null", uintptr(0), true}, nil, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/zero", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", expectArgs{"/host/dev/zero", "/sysroot/dev/zero", uintptr(0), true}, nil, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/full", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", expectArgs{"/host/dev/full", "/sysroot/dev/full", uintptr(0), true}, nil, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/random", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", expectArgs{"/host/dev/random", "/sysroot/dev/random", uintptr(0), true}, nil, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/urandom", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", expectArgs{"/host/dev/urandom", "/sysroot/dev/urandom", uintptr(0), true}, nil, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/tty", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"bindMount", expectArgs{"/host/dev/tty", "/sysroot/dev/tty", uintptr(0), true}, nil, nil},
+			{"symlink", expectArgs{"/proc/self/fd/0", "/sysroot/dev/stdin"}, nil, nil},
+			{"symlink", expectArgs{"/proc/self/fd/1", "/sysroot/dev/stdout"}, nil, nil},
+			{"symlink", expectArgs{"/proc/self/fd/2", "/sysroot/dev/stderr"}, nil, nil},
+			{"symlink", expectArgs{"/proc/self/fd", "/sysroot/dev/fd"}, nil, nil},
+			{"symlink", expectArgs{"/proc/kcore", "/sysroot/dev/core"}, nil, nil},
+			{"symlink", expectArgs{"pts/ptmx", "/sysroot/dev/ptmx"}, nil, nil},
+			{"mkdir", expectArgs{"/sysroot/dev/shm", os.FileMode(0750)}, nil, nil},
+			{"mkdir", expectArgs{"/sysroot/dev/pts", os.FileMode(0750)}, nil, nil},
+			{"mount", expectArgs{"devpts", "/sysroot/dev/pts", "devpts", uintptr(0xa), "newinstance,ptmxmode=0666,mode=620"}, nil, nil},
+			{"isatty", expectArgs{1}, true, nil},
+			{"ensureFile", expectArgs{"/sysroot/dev/console", os.FileMode(0444), os.FileMode(0750)}, nil, nil},
+			{"readlink", expectArgs{"/host/proc/self/fd/1"}, "/dev/pts/2", nil},
+			{"bindMount", expectArgs{"/host/dev/pts/2", "/sysroot/dev/console", uintptr(0), false}, nil, nil},
+			{"remount", expectArgs{"/sysroot/dev", uintptr(1)}, nil, errUnique},
+		}, errUnique},
+
 		{"success no mqueue", &Params{ParentPerm: 0750, RetainSession: true}, &MountDevOp{
 			Target: MustAbs("/dev/"),
 		}, nil, nil, []kexpect{

container/initmkdir.go

@@ -23,7 +23,7 @@ type MkdirOp struct {
 func (m *MkdirOp) Valid() bool                                { return m != nil && m.Path != nil }
 func (m *MkdirOp) early(*setupState, syscallDispatcher) error { return nil }
 func (m *MkdirOp) apply(_ *setupState, k syscallDispatcher) error {
-	return wrapErrSelf(k.mkdirAll(toSysroot(m.Path.String()), m.Perm))
+	return k.mkdirAll(toSysroot(m.Path.String()), m.Perm)
 }
 
 func (m *MkdirOp) Is(op Op) bool {

container/initoverlay.go

@@ -102,7 +102,7 @@ func (o *MountOverlayOp) early(_ *setupState, k syscallDispatcher) error {
 
 		if o.Upper != nil {
 			if v, err := k.evalSymlinks(o.Upper.String()); err != nil {
-				return wrapErrSelf(err)
+				return err
 			} else {
 				o.upper = EscapeOverlayDataSegment(toHost(v))
 			}
@@ -110,7 +110,7 @@ func (o *MountOverlayOp) early(_ *setupState, k syscallDispatcher) error {
 
 		if o.Work != nil {
 			if v, err := k.evalSymlinks(o.Work.String()); err != nil {
-				return wrapErrSelf(err)
+				return err
 			} else {
 				o.work = EscapeOverlayDataSegment(toHost(v))
 			}
@@ -120,7 +120,7 @@ func (o *MountOverlayOp) early(_ *setupState, k syscallDispatcher) error {
 	o.lower = make([]string, len(o.Lower))
 	for i, a := range o.Lower { // nil checked in Valid
 		if v, err := k.evalSymlinks(a.String()); err != nil {
-			return wrapErrSelf(err)
+			return err
 		} else {
 			o.lower[i] = EscapeOverlayDataSegment(toHost(v))
 		}
@@ -134,17 +134,17 @@ func (o *MountOverlayOp) apply(state *setupState, k syscallDispatcher) error {
 		target = toSysroot(target)
 	}
 	if err := k.mkdirAll(target, state.ParentPerm); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 
 	if o.ephemeral {
 		var err error
 		// these directories are created internally, therefore early (absolute, symlink, prefix, escape) is bypassed
 		if o.upper, err = k.mkdirTemp(FHSRoot, intermediatePatternOverlayUpper); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 		if o.work, err = k.mkdirTemp(FHSRoot, intermediatePatternOverlayWork); err != nil {
-			return wrapErrSelf(err)
+			return err
 		}
 	}
 

container/initoverlay_test.go

@@ -31,7 +31,7 @@ func TestMountOverlayOp(t *testing.T) {
 		}, nil, []kexpect{
 			{"mkdirAll", expectArgs{"/sysroot", os.FileMode(0705)}, nil, nil},
 			{"mkdirTemp", expectArgs{"/", "overlay.upper.*"}, "overlay.upper.32768", errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mkdirTemp work ephemeral", &Params{ParentPerm: 0705}, &MountOverlayOp{
 			Target: MustAbs("/"),
@@ -47,7 +47,7 @@ func TestMountOverlayOp(t *testing.T) {
 			{"mkdirAll", expectArgs{"/sysroot", os.FileMode(0705)}, nil, nil},
 			{"mkdirTemp", expectArgs{"/", "overlay.upper.*"}, "overlay.upper.32768", nil},
 			{"mkdirTemp", expectArgs{"/", "overlay.work.*"}, "overlay.work.32768", errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"success ephemeral", &Params{ParentPerm: 0705}, &MountOverlayOp{
 			Target: MustAbs("/"),
@@ -138,7 +138,7 @@ func TestMountOverlayOp(t *testing.T) {
 			Work:   MustAbs("/mnt-root/nix/.rw-store/work"),
 		}, []kexpect{
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.rw-store/upper"}, "/mnt-root/nix/.rw-store/.upper", errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"evalSymlinks work", &Params{ParentPerm: 0700}, &MountOverlayOp{
 			Target: MustAbs("/nix/store"),
@@ -148,7 +148,7 @@ func TestMountOverlayOp(t *testing.T) {
 		}, []kexpect{
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.rw-store/upper"}, "/mnt-root/nix/.rw-store/.upper", nil},
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.rw-store/work"}, "/mnt-root/nix/.rw-store/.work", errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"evalSymlinks lower", &Params{ParentPerm: 0700}, &MountOverlayOp{
 			Target: MustAbs("/nix/store"),
@@ -159,7 +159,7 @@ func TestMountOverlayOp(t *testing.T) {
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.rw-store/upper"}, "/mnt-root/nix/.rw-store/.upper", nil},
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.rw-store/work"}, "/mnt-root/nix/.rw-store/.work", nil},
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.ro-store"}, "/mnt-root/nix/ro-store", errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"mkdirAll", &Params{ParentPerm: 0700}, &MountOverlayOp{
 			Target: MustAbs("/nix/store"),
@@ -172,7 +172,7 @@ func TestMountOverlayOp(t *testing.T) {
 			{"evalSymlinks", expectArgs{"/mnt-root/nix/.ro-store"}, "/mnt-root/nix/ro-store", nil},
 		}, nil, []kexpect{
 			{"mkdirAll", expectArgs{"/sysroot/nix/store", os.FileMode(0700)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"mount", &Params{ParentPerm: 0700}, &MountOverlayOp{
 			Target: MustAbs("/nix/store"),

container/initplace.go

@@ -39,13 +39,11 @@ func (t *TmpfileOp) early(*setupState, syscallDispatcher) error { return nil }
 func (t *TmpfileOp) apply(state *setupState, k syscallDispatcher) error {
 	var tmpPath string
 	if f, err := k.createTemp(FHSRoot, intermediatePatternTmpfile); err != nil {
-		return wrapErrSelf(err)
+		return err
 	} else if _, err = f.Write(t.Data); err != nil {
-		return wrapErrSuffix(err,
-			"cannot write to intermediate file:")
+		return err
 	} else if err = f.Close(); err != nil {
-		return wrapErrSuffix(err,
-			"cannot close intermediate file:")
+		return err
 	} else {
 		tmpPath = f.Name()
 	}
@@ -61,7 +59,7 @@ func (t *TmpfileOp) apply(state *setupState, k syscallDispatcher) error {
 	); err != nil {
 		return err
 	} else if err = k.remove(tmpPath); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 	return nil
 }

container/initplace_test.go

@@ -18,21 +18,21 @@ func TestTmpfileOp(t *testing.T) {
 			Data: sampleData,
 		}, nil, nil, []kexpect{
 			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"Write", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []kexpect{
 			{"createTemp", expectArgs{"/", "tmp.*"}, writeErrOsFile{errUnique}, nil},
-		}, wrapErrSuffix(errUnique, "cannot write to intermediate file:")},
+		}, errUnique},
 
 		{"Close", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,
 			Data: sampleData,
 		}, nil, nil, []kexpect{
 			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, errUnique), nil},
-		}, wrapErrSuffix(errUnique, "cannot close intermediate file:")},
+		}, errUnique},
 
 		{"ensureFile", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,
@@ -59,7 +59,7 @@ func TestTmpfileOp(t *testing.T) {
 			{"ensureFile", expectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil},
 			{"bindMount", expectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil},
 			{"remove", expectArgs{"tmp.32768"}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"success", &Params{ParentPerm: 0700}, &TmpfileOp{
 			Path: samplePath,

container/initproc.go

@@ -22,7 +22,7 @@ func (p *MountProcOp) early(*setupState, syscallDispatcher) error { return nil }
 func (p *MountProcOp) apply(state *setupState, k syscallDispatcher) error {
 	target := toSysroot(p.Target.String())
 	if err := k.mkdirAll(target, state.ParentPerm); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 	return k.mount(SourceProc, target, FstypeProc, MS_NOSUID|MS_NOEXEC|MS_NODEV, zeroString)
 }

container/initproc_test.go

@@ -12,7 +12,7 @@ func TestMountProcOp(t *testing.T) {
 				Target: MustAbs("/proc/"),
 			}, nil, nil, []kexpect{
 				{"mkdirAll", expectArgs{"/sysroot/proc", os.FileMode(0755)}, nil, errUnique},
-			}, wrapErrSelf(errUnique)},
+			}, errUnique},
 
 		{"success", &Params{ParentPerm: 0700},
 			&MountProcOp{

container/initsymlink.go

@@ -32,7 +32,7 @@ func (l *SymlinkOp) early(_ *setupState, k syscallDispatcher) error {
 			return &AbsoluteError{l.LinkName}
 		}
 		if name, err := k.readlink(l.LinkName); err != nil {
-			return wrapErrSelf(err)
+			return err
 		} else {
 			l.LinkName = name
 		}
@@ -43,9 +43,9 @@ func (l *SymlinkOp) early(_ *setupState, k syscallDispatcher) error {
 func (l *SymlinkOp) apply(state *setupState, k syscallDispatcher) error {
 	target := toSysroot(l.Target.String())
 	if err := k.mkdirAll(path.Dir(target), state.ParentPerm); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
-	return wrapErrSelf(k.symlink(l.LinkName, target))
+	return k.symlink(l.LinkName, target)
 }
 
 func (l *SymlinkOp) Is(op Op) bool {

container/initsymlink_test.go

@@ -12,7 +12,7 @@ func TestSymlinkOp(t *testing.T) {
 			LinkName: "/etc/static/nixos",
 		}, nil, nil, []kexpect{
 			{"mkdirAll", expectArgs{"/sysroot/etc", os.FileMode(0700)}, nil, errUnique},
-		}, wrapErrSelf(errUnique)},
+		}, errUnique},
 
 		{"abs", &Params{ParentPerm: 0755}, &SymlinkOp{
 			Target:      MustAbs("/etc/mtab"),
@@ -26,7 +26,7 @@ func TestSymlinkOp(t *testing.T) {
 			Dereference: true,
 		}, []kexpect{
 			{"readlink", expectArgs{"/etc/mtab"}, "/proc/mounts", errUnique},
-		}, wrapErrSelf(errUnique), nil, nil},
+		}, errUnique, nil, nil},
 
 		{"success noderef", &Params{ParentPerm: 0700}, &SymlinkOp{
 			Target:   MustAbs("/etc/nixos"),

container/mount.go

@@ -118,7 +118,7 @@ func (p *procPaths) remount(target string, flags uintptr) error {
 
 	var targetFinal string
 	if v, err := p.k.evalSymlinks(target); err != nil {
-		return wrapErrSelf(err)
+		return err
 	} else {
 		targetFinal = v
 		if targetFinal != target {
@@ -134,14 +134,12 @@ func (p *procPaths) remount(target string, flags uintptr) error {
 			destFd, err = p.k.open(targetFinal, O_PATH|O_CLOEXEC, 0)
 			return
 		}); err != nil {
-			return wrapErrSuffix(err,
-				fmt.Sprintf("cannot open %q:", targetFinal))
+			return &os.PathError{Op: "open", Path: targetFinal, Err: err}
 		}
 		if v, err := p.k.readlink(p.fd(destFd)); err != nil {
-			return wrapErrSelf(err)
+			return err
 		} else if err = p.k.close(destFd); err != nil {
-			return wrapErrSuffix(err,
-				fmt.Sprintf("cannot close %q:", targetFinal))
+			return &os.PathError{Op: "close", Path: targetFinal, Err: err}
 		} else {
 			targetKFinal = v
 		}
@@ -202,7 +200,7 @@ func mountTmpfs(k syscallDispatcher, fsname, target string, flags uintptr, size
 	// syscallDispatcher.mountTmpfs must not be called from this function
 
 	if err := k.mkdirAll(target, parentPerm(perm)); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 	opt := fmt.Sprintf("mode=%#o", perm)
 	if size > 0 {

container/mount_test.go

@@ -83,14 +83,14 @@ func TestRemount(t *testing.T) {
 			return newProcPaths(k, hostPath).remount("/sysroot/nix", syscall.MS_REC|syscall.MS_RDONLY|syscall.MS_NODEV)
 		}, [][]kexpect{{
 			{"evalSymlinks", expectArgs{"/sysroot/nix"}, "/sysroot/nix", errUnique},
-		}}, wrapErrSelf(errUnique)},
+		}}, errUnique},
 
 		{"open", func(k syscallDispatcher) error {
 			return newProcPaths(k, hostPath).remount("/sysroot/nix", syscall.MS_REC|syscall.MS_RDONLY|syscall.MS_NODEV)
 		}, [][]kexpect{{
 			{"evalSymlinks", expectArgs{"/sysroot/nix"}, "/sysroot/nix", nil},
 			{"open", expectArgs{"/sysroot/nix", 0x280000, uint32(0)}, 0xdeadbeef, errUnique},
-		}}, wrapErrSuffix(errUnique, `cannot open "/sysroot/nix":`)},
+		}}, errUnique},
 
 		{"readlink", func(k syscallDispatcher) error {
 			return newProcPaths(k, hostPath).remount("/sysroot/nix", syscall.MS_REC|syscall.MS_RDONLY|syscall.MS_NODEV)
@@ -98,7 +98,7 @@ func TestRemount(t *testing.T) {
 			{"evalSymlinks", expectArgs{"/sysroot/nix"}, "/sysroot/nix", nil},
 			{"open", expectArgs{"/sysroot/nix", 0x280000, uint32(0)}, 0xdeadbeef, nil},
 			{"readlink", expectArgs{"/host/proc/self/fd/3735928559"}, "/sysroot/nix", errUnique},
-		}}, wrapErrSelf(errUnique)},
+		}}, errUnique},
 
 		{"close", func(k syscallDispatcher) error {
 			return newProcPaths(k, hostPath).remount("/sysroot/nix", syscall.MS_REC|syscall.MS_RDONLY|syscall.MS_NODEV)
@@ -107,7 +107,7 @@ func TestRemount(t *testing.T) {
 			{"open", expectArgs{"/sysroot/nix", 0x280000, uint32(0)}, 0xdeadbeef, nil},
 			{"readlink", expectArgs{"/host/proc/self/fd/3735928559"}, "/sysroot/nix", nil},
 			{"close", expectArgs{0xdeadbeef}, nil, errUnique},
-		}}, wrapErrSuffix(errUnique, `cannot close "/sysroot/nix":`)},
+		}}, errUnique},
 
 		{"mountinfo stale", func(k syscallDispatcher) error {
 			return newProcPaths(k, hostPath).remount("/sysroot/nix", syscall.MS_REC|syscall.MS_RDONLY|syscall.MS_NODEV)
@@ -243,7 +243,7 @@ func TestMountTmpfs(t *testing.T) {
 			return mountTmpfs(k, "ephemeral", "/sysroot/run/user/1000", 0, 1<<10, 0700)
 		}, [][]kexpect{{
 			{"mkdirAll", expectArgs{"/sysroot/run/user/1000", os.FileMode(0700)}, nil, errUnique},
-		}}, wrapErrSelf(errUnique)},
+		}}, errUnique},
 
 		{"success no size", func(k syscallDispatcher) error {
 			return mountTmpfs(k, "ephemeral", "/sysroot/run/user/1000", 0, 0, 0710)

container/output.go

@@ -17,10 +17,3 @@ func wrapErrSuffix(err error, a ...any) error {
 	}
 	return msg.WrapErr(err, append(a, err)...)
 }
-
-func wrapErrSelf(err error) error {
-	if err == nil {
-		return nil
-	}
-	return msg.WrapErr(err, err.Error())
-}

container/output_test.go

@@ -58,16 +58,6 @@ func TestWrapErr(t *testing.T) {
 				t.Errorf("wrapErrSuffix: %v", err)
 			}
 		}, syscall.ENOTRECOVERABLE, []any{"\x00\x00", syscall.ENOTRECOVERABLE}},
-		{"self nil", func(t *testing.T) {
-			if err := wrapErrSelf(nil); err != nil {
-				t.Errorf("wrapErrSelf: %v", err)
-			}
-		}, nil, nil},
-		{"self val", func(t *testing.T) {
-			if err := wrapErrSelf(syscall.ENOTRECOVERABLE); err != syscall.ENOTRECOVERABLE {
-				t.Errorf("wrapErrSelf: %v", err)
-			}
-		}, syscall.ENOTRECOVERABLE, []any{"state not recoverable"}},
 	}
 
 	for _, tc := range testCases {

container/path.go

@@ -2,7 +2,6 @@ package container
 
 import (
 	"errors"
-	"fmt"
 	"io/fs"
 	"os"
 	"path"
@@ -103,30 +102,29 @@ func toHost(name string) string {
 
 func createFile(name string, perm, pperm os.FileMode, content []byte) error {
 	if err := os.MkdirAll(path.Dir(name), pperm); err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 	f, err := os.OpenFile(name, syscall.O_CREAT|syscall.O_EXCL|syscall.O_WRONLY, perm)
 	if err != nil {
-		return wrapErrSelf(err)
+		return err
 	}
 	if content != nil {
 		_, err = f.Write(content)
 	}
-	return errors.Join(f.Close(), wrapErrSelf(err))
+	return errors.Join(f.Close(), err)
 }
 
 func ensureFile(name string, perm, pperm os.FileMode) error {
 	fi, err := os.Stat(name)
 	if err != nil {
 		if !os.IsNotExist(err) {
-			return wrapErrSelf(err)
+			return err
 		}
 		return createFile(name, perm, pperm, nil)
 	}
 
 	if mode := fi.Mode(); mode&fs.ModeDir != 0 || mode&fs.ModeSymlink != 0 {
-		err = msg.WrapErr(syscall.EISDIR,
-			fmt.Sprintf("path %q is a directory", name))
+		err = &os.PathError{Op: "ensure", Path: name, Err: syscall.EISDIR}
 	}
 	return err
 }
@@ -147,12 +145,12 @@ func (p *procPaths) stdout() string   { return p.self + "/fd/1" }
 func (p *procPaths) fd(fd int) string { return p.self + "/fd/" + strconv.Itoa(fd) }
 func (p *procPaths) mountinfo(f func(d *vfs.MountInfoDecoder) error) error {
 	if r, err := p.k.openNew(p.self + "/mountinfo"); err != nil {
-		return wrapErrSelf(err)
+		return err
 	} else {
 		d := vfs.NewMountInfoDecoder(r)
 		err0 := f(d)
 		if err = r.Close(); err != nil {
-			return wrapErrSelf(err)
+			return err
 		} else if err = d.Err(); err != nil {
 			return wrapErrSuffix(err,
 				"cannot parse mountinfo:")

container/path_test.go

@@ -2,7 +2,6 @@ package container
 
 import (
 	"errors"
-	"fmt"
 	"io"
 	"math"
 	"os"
@@ -56,20 +55,27 @@ func InternalToHostOvlEscape(s string) string { return EscapeOverlayDataSegment(
 
 func TestCreateFile(t *testing.T) {
 	t.Run("nonexistent", func(t *testing.T) {
-		if err := createFile(path.Join(Nonexistent, ":3"), 0644, 0755, nil); !errors.Is(err, wrapErrSelf(&os.PathError{
+		t.Run("mkdir", func(t *testing.T) {
+			wantErr := &os.PathError{
 				Op:   "mkdir",
 				Path: "/proc/nonexistent",
 				Err:  syscall.ENOENT,
-		})) {
-			t.Errorf("createFile: error = %v", err)
 			}
-		if err := createFile(path.Join(Nonexistent), 0644, 0755, nil); !errors.Is(err, wrapErrSelf(&os.PathError{
+			if err := createFile(path.Join(Nonexistent, ":3"), 0644, 0755, nil); !reflect.DeepEqual(err, wantErr) {
+				t.Errorf("createFile: error = %#v, want %#v", err, wantErr)
+			}
+		})
+
+		t.Run("open", func(t *testing.T) {
+			wantErr := &os.PathError{
 				Op:   "open",
 				Path: "/proc/nonexistent",
 				Err:  syscall.ENOENT,
-		})) {
-			t.Errorf("createFile: error = %v", err)
 			}
+			if err := createFile(path.Join(Nonexistent), 0644, 0755, nil); !reflect.DeepEqual(err, wantErr) {
+				t.Errorf("createFile: error = %#v, want %#v", err, wantErr)
+			}
+		})
 	})
 
 	t.Run("touch", func(t *testing.T) {
@@ -120,13 +126,13 @@ func TestEnsureFile(t *testing.T) {
 				t.Fatalf("Chmod: error = %v", err)
 			}
 
-			wantErr := wrapErrSelf(&os.PathError{
+			wantErr := &os.PathError{
 				Op:   "stat",
 				Path: pathname,
 				Err:  syscall.EACCES,
-			})
-			if err := ensureFile(pathname, 0644, 0755); !errors.Is(err, wantErr) {
-				t.Errorf("ensureFile: error = %v, want %v", err, wantErr)
+			}
+			if err := ensureFile(pathname, 0644, 0755); !reflect.DeepEqual(err, wantErr) {
+				t.Errorf("ensureFile: error = %#v, want %#v", err, wantErr)
 			}
 
 			if err := os.Chmod(tempDir, 0755); err != nil {
@@ -136,9 +142,9 @@ func TestEnsureFile(t *testing.T) {
 
 		t.Run("directory", func(t *testing.T) {
 			pathname := t.TempDir()
-			wantErr := msg.WrapErr(syscall.EISDIR, fmt.Sprintf("path %q is a directory", pathname))
-			if err := ensureFile(pathname, 0644, 0755); !errors.Is(err, wantErr) {
-				t.Errorf("ensureFile: error = %v, want %v", err, wantErr)
+			wantErr := &os.PathError{Op: "ensure", Path: pathname, Err: syscall.EISDIR}
+			if err := ensureFile(pathname, 0644, 0755); !reflect.DeepEqual(err, wantErr) {
+				t.Errorf("ensureFile: error = %#v, want %#v", err, wantErr)
 			}
 		})
 
@@ -177,12 +183,12 @@ func TestProcPaths(t *testing.T) {
 	t.Run("mountinfo", func(t *testing.T) {
 		t.Run("nonexistent", func(t *testing.T) {
 			nonexistentProc := newProcPaths(direct{}, t.TempDir())
-			wantErr := wrapErrSelf(&os.PathError{
+			wantErr := &os.PathError{
 				Op:   "open",
 				Path: nonexistentProc.self + "/mountinfo",
 				Err:  syscall.ENOENT,
-			})
-			if err := nonexistentProc.mountinfo(func(*vfs.MountInfoDecoder) error { return syscall.EINVAL }); !errors.Is(err, wantErr) {
+			}
+			if err := nonexistentProc.mountinfo(func(*vfs.MountInfoDecoder) error { return syscall.EINVAL }); !reflect.DeepEqual(err, wantErr) {
 				t.Errorf("mountinfo: error = %v, want %v", err, wantErr)
 			}
 		})
@@ -217,11 +223,11 @@ func TestProcPaths(t *testing.T) {
 
 			t.Run("closed", func(t *testing.T) {
 				p := newProcPaths(direct{}, tempDir)
-				wantErr := wrapErrSelf(&os.PathError{
+				wantErr := &os.PathError{
 					Op:   "close",
 					Path: p.self + "/mountinfo",
 					Err:  os.ErrClosed,
-				})
+				}
 				if err := p.mountinfo(func(d *vfs.MountInfoDecoder) error {
 					v := reflect.ValueOf(d).Elem().FieldByName("s").Elem().FieldByName("r")
 					v = reflect.NewAt(v.Type(), unsafe.Pointer(v.UnsafeAddr()))
@@ -231,8 +237,8 @@ func TestProcPaths(t *testing.T) {
 					} else {
 						return f.Close()
 					}
-				}); !errors.Is(err, wantErr) {
-					t.Errorf("mountinfo: error = %v, want %v", err, wantErr)
+				}); !reflect.DeepEqual(err, wantErr) {
+					t.Errorf("mountinfo: error = %#v, want %#v", err, wantErr)
 				}
 			})