def test_safe_wait_INADDR_ANY():  # pylint: disable=invalid-name
    """Wait on INADDR_ANY should not raise IOError.

    In cases where the loopback interface does not exist, CherryPy
    cannot effectively determine if a port binding to INADDR_ANY was
    effected. In this situation, CherryPy should assume that it failed
    to detect the binding (not that the binding failed) and only warn
    that it could not verify it.
    """
    # At such a time that CherryPy can reliably determine one or more
    #  viable IP addresses of the host, this test may be removed.

    # Simulate the behavior we observe when no loopback interface is
    #  present by: finding a port that's not occupied, then wait on it.

    free_port = portend.find_available_local_port()

    servers = cherrypy.process.servers

    inaddr_any = '0.0.0.0'

    # Wait on the free port that's unbound
    with pytest.warns(
        UserWarning,
        match='Unable to verify that the server is bound on ',
    ) as warnings:
        # pylint: disable=protected-access
        with servers._safe_wait(inaddr_any, free_port):
            portend.occupied(inaddr_any, free_port, timeout=1)
    assert len(warnings) == 1

    # The wait should still raise an IO error if INADDR_ANY was
    #  not supplied.
    with pytest.raises(IOError):
        # pylint: disable=protected-access
        with servers._safe_wait('127.0.0.1', free_port):
            portend.occupied('127.0.0.1', free_port, timeout=1)
Wait on INADDR_ANY should not raise IOError.

    In cases where the loopback interface does not exist, CherryPy
    cannot effectively determine if a port binding to INADDR_ANY was
    effected. In this situation, CherryPy should assume that it failed
    to detect the binding (not that the binding failed) and only warn
    that it could not verify it.
    
cherrypy/test/test_states.py