code: func joinImportPath(baseDir, dir string) string {
  	baseDirElems := strings.Split(baseDir, string(filepath.Separator))
  	dirElems := strings.Split(dir, string(filepath.Separator))
  	elems := append(baseDirElems, dirElems...)
  	return path.Join(elems...)
  }
docs: // joinImportPath should always use `/`.
  // this is not the case in windows.
  // so we need to split it based on file separator and then join again using `/`