> Do you see other failures?

I applied your patch and I just replace the hasattr with:
hasattr(_socket, "Xsocketpair"). test_socket failures:

======================================================================
FAIL: test_sendall_interrupted (test.test_socket.GeneralModuleTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
1259, in test_sendall_interrupted
    self.check_sendall_interrupted(False)
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
1248, in check_sendall_interrupted
    c.sendall(b"x" * (1024**2))
AssertionError: ZeroDivisionError not raised

======================================================================
FAIL: test_sendall_interrupted_with_timeout
(test.test_socket.GeneralModuleTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
1262, in test_sendall_interrupted_with_timeout
    self.check_sendall_interrupted(True)
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
1248, in check_sendall_interrupted
    c.sendall(b"x" * (1024**2))
AssertionError: ZeroDivisionError not raised

======================================================================
FAIL: testDefaults (test.test_socket.BasicSocketPairTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
3640, in testDefaults
    self._check_defaults(self.serv)
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
3630, in _check_defaults
    self.assertEqual(sock.family, socket.AF_UNIX)
AssertionError: 2 != 1

======================================================================
FAIL: testDefaults (test.test_socket.BasicSocketPairTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
261, in _tearDown
    raise exc
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
273, in clientRun
    test_func()
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
3637, in _testDefaults
    self._check_defaults(self.cli)
  File "/home/haypo/prog/python/default/Lib/test/test_socket.py", line
3630, in _check_defaults
    self.assertEqual(sock.family, socket.AF_UNIX)
AssertionError: 2 != 1