code: func (*LinuxStrategy) chown(c context.Context, path, username string) error {
  	u, err := user.Lookup(username)
  	if err != nil {
  		return errors.Annotate(err, "failed to look up local user %q", username).Err()
  	}
  	uid, err := strconv.Atoi(u.Uid)
  	if err != nil {
  		return errors.Annotate(err, "failed to get uid for user %q", username).Err()
  	}
  	gid, err := strconv.Atoi(u.Gid)
  	if err != nil {
  		return errors.Annotate(err, "failed to get gid for user %q", username).Err()
  	}
  	return os.Chown(path, uid, gid)
  }
docs: // chown modifies the given path to be owned by the given user.
  // Implements PlatformStrategy.