docs: def find_repositories_by_walking_without_following_symlinks(path):
      """Walk a tree and return a sequence of (directory, dotdir) pairs."""
      repos = []
      for dirpath, dirnames, filenames in os.walk(path, followlinks=False):
          for dotdir in set(dirnames) & DOTDIRS:
              repos.append((dirpath, dotdir))
      return repos