strings.Join(args, " "), output, err)
	}

	files, err := ioutil.ReadDir(dir)
	if err != nil {
		return err
	}

	if len(b.revision) == 0 {
		// Done!
		volumeutil.SetReady(b.getMetaDir())
		return nil
	}

	var subdir string

	switch {
	case len(b.target) != 0 && filepath.Clean(b.target) == ".":
		// if target dir is '.', use the current dir