I nearly have a patch - to resolve all the remaining test_socket() issues with AIX. However, this (new?) issue remains:

        f = lambda a: inet_pton(AF_INET6, a)
        assertInvalid = lambda a: self.assertRaises(
            (OSError, ValueError), f, a
        )

>>> f('1:2:3:4:5:6:7:8')
b'\x00\x01\x00\x02\x00\x03\x00\x04\x00\x05\x00\x06\x00\x07\x00\x08'
>>> f('1:2:3:4:5:6:7:8:')
b'\x00\x01\x00\x02\x00\x03\x00\x04\x00\x05\x00\x06\x00\x07\x00\x08'
>>> f('1::')
b'\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
>>> f('1:2:3:4:5:6:7:8::')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <lambda>
OSError: illegal IP address string passed to inet_pton

>>> f('1:2:3:4:5:6:7')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 1, in <lambda>
OSError: illegal IP address string passed to inet_pton


Is, maybe, the last test meant to be '::' on the end, rather than ':'?