docs: def open_repository(path, spor_dir='.spor'):
      """Open an existing repository.
  
      Args:
          path: Path to any file or directory within the repository.
          spor_dir: The name of the directory containing spor data.
  
      Returns: A `Repository` instance.
  
      Raises:
          ValueError: No repository is found.
      """
      root = _find_root_dir(path, spor_dir)
      return Repository(root, spor_dir)