docs: def print_lines(process: Popen) -> None:
      """
      Let a subprocess :func:`communicate`, then write both its ``stdout`` and
      its ``stderr`` to our ``stdout``.
      """
      out, err = process.communicate()
      if out:
          for line in out.decode("utf-8").splitlines():
              print(line)
      if err:
          for line in err.decode("utf-8").splitlines():
              print(line)