code: func NormalizedOSTempDirPath(tmpDirNamePrefix string) (retPth string, err error) {
  	retPth, err = ioutil.TempDir("", tmpDirNamePrefix)
  	if strings.HasSuffix(retPth, "/") {
  		retPth = retPth[:len(retPth)-1]
  	}
  	return
  }
docs: // NormalizedOSTempDirPath ...
  // Creates a temp dir, and returns its path.
  // If tmpDirNamePrefix is provided it'll be used
  //  as the tmp dir's name prefix.
  // Normalized: it's guaranteed that the path won't end with '/'.