Hello! The attached patch fixes a crash for the logging tests on Windows. That's because the tests assume that socket.AF_UNIX exists. The actual traceback is:

[1/1] test_logging
test test_logging crashed -- Traceback (most recent call last):
  File "D:\Projects\cpython\lib\test\regrtest.py", line 1271, in runtest_inner
    the_module = importlib.import_module(abstest)
  File "D:\Projects\cpython\lib\importlib\__init__.py", line 109, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 2203, in _gcd_import
  File "<frozen importlib._bootstrap>", line 2186, in _find_and_load
  File "<frozen importlib._bootstrap>", line 2175, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1149, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1420, in exec_module
  File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
  File "D:\Projects\cpython\lib\test\test_logging.py", line 863, in <module>
    class TestUnixStreamServer(TestTCPServer):
  File "D:\Projects\cpython\lib\test\test_logging.py", line 864, in TestUnixStreamServer
    address_family = socket.AF_UNIX
AttributeError: module 'socket' has no attribute 'AF_UNIX'

1 test failed:
    test_logging

Oh, it looks like a follow-up of the issue #21583 (change f1393e82660819996e74c7eeddc5ae1f38b15f0a), the test was already buggy but not run before.

+    if threading and hasattr(socket, "AF_UNIX"):

The check on socket.AF_UNIX attribute looks redundant: there is already a decorator on the testcase class to skip the whole test case. No?

No, because the tests will be skipped after the assignment of the address family.

> No, because the tests will be skipped after the assignment of the address family.

Ah yes, the body of the class is executed before the decorator.

New changeset d7a491c6cbdb by Victor Stinner in branch '3.4':
Issue #21636: Fix test_logging, skip UNIX stream (AF_UNIX) tests on Windows.
http://hg.python.org/cpython/rev/d7a491c6cbdb

New changeset b49e366556ba by Victor Stinner in branch 'default':
(Merge 3.4) Issue #21636: Fix test_logging, skip UNIX stream (AF_UNIX) tests on
http://hg.python.org/cpython/rev/b49e366556ba