docs: def _build_tarball(src_repo) -> str:
      """ Build a tarball from src and return the path to it """
      run = partial(subprocess.run, cwd=src_repo, check=True)
      run(['git', 'clean', '-xdff'])
      src_repo = Path(src_repo)
      if os.path.exists(src_repo / 'es' / 'upstream'):
          run(['git', 'submodule', 'update', '--init', '--', 'es/upstream'])
      run(['./gradlew', '--no-daemon', 'clean', 'distTar'])
      distributions = Path(src_repo) / 'app' / 'build' / 'distributions'
      return next(distributions.glob('crate-*.tar.gz'))