code: func transformVersion(v string) string {
  	if v == "unknown-dev" {
  		return v
  	}
  	if !strings.HasPrefix(v, "v") {
  		v = "v" + v
  	}
  	v = plusRe.ReplaceAllString(v, " "+plusStr)
  
  	return v
  }
docs: // transformVersion returns a version number formatted correctly, with all
  // development versions aggregated into one.