'If the underlying C{recvmsg} call fails, L{recv1msg} raises
L{socket.error} with its errno set to the underlying errno value.'

def test_syscallError(self):

    with open(devnull) as probe:
        fd = probe.fileno()
    exc = self.assertRaises(error, recv1msg, fd)
    self.assertEqual(exc.args[0], errno.EBADF)
