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)
Let a subprocess :func:`communicate`, then write both its ``stdout`` and
    its ``stderr`` to our ``stdout``.