test_multiprocessing fails on platforms lacking a functioning sem_open (Android for example) with:

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ERROR: test_multiprocessing (test.test_venv.BasicTest)
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Traceback (most recent call last):
  File "/data/local/tmp/python/lib/python3.8/test/test_venv.py", line 317, in test_multiprocessing
    out, err = check_output([envpy, '-c',
  File "/data/local/tmp/python/lib/python3.8/test/test_venv.py", line 37, in check_output
    raise subprocess.CalledProcessError(
subprocess.CalledProcessError: Command '['/data/local/tmp/python/tmp/tmpli0_hkdl/bin/python', '-c', 'from multiprocessing import Pool; print(Pool(1).apply_async("Python".lower).get(3))']' returned non-zero exit status 1.