vstinner@apu$ PYTHONWARNINGS=error ./python -W error -m test test_multiprocessing_spawn -v -m test_semaphore_tracker 
== CPython 3.7.0a3+ (heads/master:747f48e2e9, Dec 12 2017, 23:12:36) [GCC 7.2.1 20170915 (Red Hat 7.2.1-2)]
== Linux-4.13.16-300.fc27.x86_64-x86_64-with-fedora-27-Twenty_Seven little-endian
== cwd: /home/vstinner/prog/python/master/build/test_python_29868
== CPU count: 8
== encodings: locale=UTF-8, FS=utf-8
Run tests sequentially
0:00:00 load avg: 0.52 [1/1] test_multiprocessing_spawn
test_semaphore_tracker (test.test_multiprocessing_spawn.TestSemaphoreTracker) ... FAIL
Exception ignored in: <_io.FileIO name=7 mode='rb' closefd=True>
ResourceWarning: unclosed file <_io.BufferedReader name=7>

======================================================================
FAIL: test_semaphore_tracker (test.test_multiprocessing_spawn.TestSemaphoreTracker)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/vstinner/prog/python/master/Lib/test/_test_multiprocessing.py", line 4380, in test_semaphore_tracker
    _multiprocessing.sem_unlink(name2)
AssertionError: OSError not raised

----------------------------------------------------------------------
Ran 1 test in 2.060s

FAILED (failures=1)
test test_multiprocessing_spawn failed
test_multiprocessing_spawn failed

1 test failed:
    test_multiprocessing_spawn

Total duration: 2 sec
Tests result: FAILURE