copy: no check sigs for chroot store

copy.go

@@ -19,6 +19,10 @@ func Copy(ctx Context, store Store, installables iter.Seq[string]) error {
 		FlagTo, store.String(),
 		FlagStdin)
 	cmd.Env = append(os.Environ(), store.Environ()...)
+	if _, ok := store.(Local); ok {
+		// this is required for chroot stores, but does not seem to have any effect on binary cache
+		cmd.Args = append(cmd.Args, FlagNoCheckSigs)
+	}
 
 	cmd.Stdout, cmd.Stderr = ctx.Streams()
 	_, err := ctx.WriteStdin(cmd, installables, nil)

copy_test.go

@@ -14,10 +14,15 @@ import (
 func init() {
 	stubCommandInit = append(stubCommandInit, func(c command.Command) {
 		var (
-			flagCopyTo    string
-			flagCopyStdin bool
+			flagCopyTo      string
+			flagCopyStdin   bool
+			flagNoCheckSigs bool
 		)
 		c.NewCommand(nix.CommandCopy, "emit samples for various `nix copy` cases", func(args []string) error {
+			if flagNoCheckSigs && flagCopyStdin && flagCopyTo == "/" {
+				return nil
+			}
+
 			if flagCopyTo != "s3://example?compression=none&parallel-compression=false&region=us-east-1&scheme=http&endpoint=s3.example.org&secret-key="+nonexistent || !flagCopyStdin {
 				return syscall.ENOSYS
 			}
@@ -32,7 +37,8 @@ func init() {
 			return nil
 		}).
 			Flag(&flagCopyTo, trimFlagName(nix.FlagTo), command.StringFlag(""), nix.FlagTo).
-			Flag(&flagCopyStdin, trimFlagName(nix.FlagStdin), command.BoolFlag(false), nix.FlagStdin)
+			Flag(&flagCopyStdin, trimFlagName(nix.FlagStdin), command.BoolFlag(false), nix.FlagStdin).
+			Flag(&flagNoCheckSigs, trimFlagName(nix.FlagNoCheckSigs), command.BoolFlag(false), nix.FlagNoCheckSigs)
 	})
 }
 
@@ -64,4 +70,14 @@ func TestCopy(t *testing.T) {
 			t.Errorf("Copy: error = %v, want %v", err, os.ErrInvalid)
 		}
 	})
+
+	t.Run("chroot store", func(t *testing.T) {
+		if err := nix.Copy(
+			newStubContext(t.Context(), nil, os.Stdout, os.Stderr),
+			nix.Local(os.PathSeparator),
+			slices.Values([]string{"/nix/store"}),
+		); err != nil {
+			t.Errorf("Copy: error = %v", err)
+		}
+	})
 }