pkg/chrootarchive: fix Darwin build

Before this commit, `doPack`, `doUnpack` and `doUnpackLayer` were not implemented for Darwin, causing build failure.

This change allows all non-Linux Unixes to use FreeBSD reexec-based pack/unpack implementation

See also: moby/buildkit#4059
See also: 8b843732b36541b8b8a11ecb83cf5d51837ae22f

Signed-off-by: Marat Radchenko <marat@slonopotamus.org>

pkg/chrootarchive/archive_freebsd.go → pkg/chrootarchive/archive_unix_nolinux.go

@@ -1,3 +1,5 @@
+//go:build unix && !linux
+
 package chrootarchive // import "github.com/docker/docker/pkg/chrootarchive"
 
 import (
@@ -15,9 +17,9 @@ import (
 )
 
 const (
-	packCmd        = "freebsd-pack-in-chroot"
-	unpackCmd      = "freebsd-unpack-in-chroot"
-	unpackLayerCmd = "freebsd-unpack-layer-in-chroot"
+	packCmd        = "chrootarchive-pack-in-chroot"
+	unpackCmd      = "chrootarchive-unpack-in-chroot"
+	unpackLayerCmd = "chrootarchive-unpack-layer-in-chroot"
 )
 
 func init() {

pkg/chrootarchive/archive_freebsd_test.go → pkg/chrootarchive/archive_unix_nolinux_test.go

@@ -1,3 +1,5 @@
+//go:build unix && !linux
+
 package chrootarchive // import "github.com/docker/docker/pkg/chrootarchive"
 
 import (