def get_authors(project_dir=os.curdir):
    """
    Retrieves the authors list, from the AUTHORS file (if in a package) or
    generates it from the git history.

    Returns:
        list(str): List of authors

    Raises:
        RuntimeError: If the authors could not be retrieved
    """
    authors = set()
    pkg_info_file = os.path.join(project_dir, 'PKG-INFO')
    authors_file = os.path.join(project_dir, 'AUTHORS')
    if os.path.exists(pkg_info_file) and os.path.exists(authors_file):
        with open(authors_file) as authors_fd:
            authors = set(authors_fd.read().splitlines())
    else:
        authors = api.get_authors(repo_path=project_dir)

    return authors