docs: def _find_root_dir(path, spor_dir):
      """Search for a spor repo containing `path`.
  
      This searches for `spor_dir` in directories dominating `path`. If a
      directory containing `spor_dir` is found, then that directory is returned
      as a `pathlib.Path`.
  
      Returns: The dominating directory containing `spor_dir` as a
        `pathlib.Path`.
  
      Raises:
        ValueError: No repository is found.
  
      """
  
      start_path = pathlib.Path(os.getcwd() if path is None else path)
      paths = [start_path] + list(start_path.parents)
  
      for path in paths:
          data_dir = path / spor_dir
          if data_dir.exists() and data_dir.is_dir():
              return path
  
      raise ValueError('No spor repository found')