code: func normalizeWorkdir(_ string, current string, requested string) (string, error) {
  	if requested == "" {
  		return "", errors.New("cannot normalize nothing")
  	}
  	current = filepath.FromSlash(current)
  	requested = filepath.FromSlash(requested)
  	if !filepath.IsAbs(requested) {
  		return filepath.Join(string(os.PathSeparator), current, requested), nil
  	}
  	return requested, nil
  }
docs: // normalizeWorkdir normalizes a user requested working directory in a
  // platform semantically consistent way.