======================================================================
ERROR: testFDPassEmpty (test.test_socket.RecvmsgSCMRightsStreamTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/test_socket.py", line 2799, in testFDPassEmpty
    len(MSG), 10240),
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/test_socket.py", line 1907, in doRecvmsg
    result = sock.recvmsg(bufsize, *args)
OSError: [Errno 12] Cannot allocate memory

======================================================================
ERROR: testFDPassEmpty (test.test_socket.RecvmsgIntoSCMRightsStreamTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/test_socket.py", line 2799, in testFDPassEmpty
    len(MSG), 10240),
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/test_socket.py", line 1998, in doRecvmsg
    result = sock.recvmsg_into([buf], *args)
OSError: [Errno 12] Cannot allocate memory

----------------------------------------------------------------------
Ran 507 tests in 28.819s

FAILED (errors=2, skipped=122)
test test_socket failed

Same failures seen with 3.4.3 and 3.5.0b4 installers on 10.11 (El Capitan) Developer Previews 2 and 4.  Passes on 10.10.x and earlier recent OS X systems.  There have been other problems in this area on OS X in the past (see Issue12958).  Probably need to open a RADAR.