After bpo-36867, test_multiprocessing_spawn fails running any test on Windows (but it isn't noticed as a fail build).

https://ci.appveyor.com/project/python/cpython/builds/24485897#L1264

0:04:05 load avg: 5.39 [389/421] test_multiprocessing_spawn run no tests
ERROR
======================================================================
ERROR: setUpModule (test.test_multiprocessing_spawn)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\projects\cpython\lib\test\_test_multiprocessing.py", line 5498, in setUpModule
    multiprocessing.set_forkserver_preload(PRELOAD)
  File "C:\projects\cpython\lib\multiprocessing\context.py", line 183, in set_forkserver_preload
    from .forkserver import set_forkserver_preload
  File "C:\projects\cpython\lib\multiprocessing\forkserver.py", line 14, in <module>
    from . import resource_tracker
  File "C:\projects\cpython\lib\multiprocessing\resource_tracker.py", line 24, in <module>
    import _posixshmem
ModuleNotFoundError: No module named '_posixshmem'
----------------------------------------------------------------------
Ran 0 tests in 0.005s
FAILED (errors=1)

Indeed, this is failing as well in all buildbots but has not been reported because fails in the setUp and therefore is counted as "RUN NO TESTS". Example:

https://buildbot.python.org/all/#/builders/58/builds/2368/steps/3/logs/stdio

Thanks for the fix Antoine.

New changeset 95da83d9bac698d420cc308e8699ef6e4fae2aca by Antoine Pitrou in branch 'master':
bpo-36894: Fix regression in test_multiprocessing_spawn (no tests run on Windows) (GH-13290)
https://github.com/python/cpython/commit/95da83d9bac698d420cc308e8699ef6e4fae2aca

Can this be closed?

I close the issue.

nosy: + vstinner
messages: + msg344682

resolution: fixed
stage: patch review -> resolved