Function in_systemd_nspawn_sync_suppressed

Lib/test/support/__init__.py:3151–3181

Test whether the test suite is runing in systemd-nspawn with ``--suppress-sync=true``. This can be used to skip tests that rely on ``fsync()`` calls and similar not being intercepted.

()

def in_systemd_nspawn_sync_suppressed() -> bool:
    """
    Test whether the test suite is runing in systemd-nspawn
    with ``--suppress-sync=true``.

    This can be used to skip tests that rely on ``fsync()`` calls
    and similar not being intercepted.
    """

    if not hasattr(os, "O_SYNC"):
        return False

    try:
        with open("/run/systemd/container", "rb") as fp:
            if fp.read().rstrip() != b"systemd-nspawn":
                return False
    except FileNotFoundError:
        return False

    # If systemd-nspawn is used, O_SYNC flag will immediately
    # trigger EINVAL.  Otherwise, ENOENT will be given instead.
    import errno
    try:
        fd = os.open(__file__, os.O_RDONLY | os.O_SYNC)
    except OSError as err:
        if err.errno == errno.EINVAL:
            return True
    else:
        os.close(fd)

    return False

def run_no_yield_async_fn(async_fn, /, *args, **kwargs):
    coro = async_fn(*args, **kwargs)