'Calling L{sendsmsg} with SOL_SOCKET, SCM_RIGHTS, and a platform-endian
packed file descriptor number should send that file descriptor to a
different process, where it can be retrieved by using L{recv1msg}.'

@inlineCallbacks
def test_sendSubProcessFD(self):

    sspp = _spawn('cmodulepullpipe', self.output.fileno())
    (yield sspp.started)
    (pipeOut, pipeIn) = _makePipe()
    self.addCleanup(pipeOut.close)
    self.addCleanup(pipeIn.close)
    with pipeIn:
        send1msg(self.input.fileno(), 'blonk', 0, [(SOL_SOCKET, SCM_RIGHTS, pack('i', pipeIn.fileno()))])
    (yield sspp.stopped)
    self.assertEqual(read(pipeOut.fileno(), 1024), 'Test    fixture    data:    blonk.\n')
    self.assertEqual(read(pipeOut.fileno(), 1024), '')
