[New-bugs-announce] [issue36432] Running python test suite fails on macOS 10.14.4 with resource.RLIMIT_STACK error

[Ned Deily]

New submission from Ned Deily <nad at python.org>:

After upgrading my first macOS system to the newly released macOS 10.14.4 update, attempts to run the Python test suite via regrtest fail:

$ /usr/local/bin/python3.7 -m test -uall -j3 -w
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/test/__main__.py", line 2, in <module>
    main()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/test/libregrtest/main.py", line 640, in main
    Regrtest().main(tests=tests, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/test/libregrtest/main.py", line 586, in main
    self._main(tests, kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/test/libregrtest/main.py", line 607, in _main
    setup_tests(self.ns)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/test/libregrtest/setup.py", line 77, in setup_tests
    resource.setrlimit(resource.RLIMIT_STACK, (newsoft, hard))
ValueError: current limit exceeds maximum limit

The error is during regrtest initialization when it is trying to increase the process stack size to avoid previously seen problems when running tests.  This code has been unchanged for a long time.

Stepping through the code in the REPL on 10.14.4:
>>> import resource
>>> resource.getrlimit(resource.RLIMIT_STACK)
(8388608, 67104768)
>>> soft, hard = resource.getrlimit(resource.RLIMIT_STACK)
>>> newsoft = min(hard, max(soft, 1024*2048))
>>> newsoft
8388608
>>> resource.setrlimit(resource.RLIMIT_STACK, (newsoft, hard))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: current limit exceeds maximum limit

The same code run on a macOS system still running 10.14.3 gives the same values from getrlimit but does not fail when calling setrlimit.

I will investigate further tomorrow; if this is a general problem with macOS 10.14.4, we'll need to provide a workaround and possibly open an incident report with Apple.

----------
assignee: ned.deily
components: macOS
messages: 338858
nosy: ned.deily, ronaldoussoren
priority: critical
severity: normal
stage: test needed
status: open
title: Running python test suite fails on macOS 10.14.4 with resource.RLIMIT_STACK error
versions: Python 3.7, Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue36432>
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