Segmentation fault on Python 3.14 rc1 on macOS

[MatthieuDartiailh]

Bug report

Bug description:

Running the pyclibrary testsuite on Python 3.14-rc1 segfaults on macOS (while it succeeds on Linux and Windows).

The CI job that displayed the issue is https://github.com/MatthieuDartiailh/pyclibrary/actions/runs/16865688466/job/47772236565?pr=83

CPython versions tested on:

3.14

Operating systems tested on:

macOS

[hugovk]

Are you able to create a minimal code example to reproduce this?

Tips here:

https://stackoverflow.com/help/minimal-reproducible-example

[inventshah]

Looks related to #137573 since it has the same Abort trap: 6 error. I bisected to a5274cd in the linked issue.

[inventshah]

Confirmed it has the same bad commit.

Built with -enable-experimental-jit=yes-off --with-lto=full --enable-optimizations from a5274cd and:

git clone https://github.com/MatthieuDartiailh/pyclibrary.git
cd pyclibrary

python3.14 -m venv venv
source venv/bin/activate
python -m pip install . pytest-cov pytest 
python -m pytest tests --cov pyclibrary --cov-report xml -v tests/backends/test_ctypes.py::TestCTypesCLibrary::test_call

Causes Abort trap: 6

[AA-Turner]

@inventshah are you able to minimise the crash-causing-code? Ideally without using pytest, and even better if only using stdlib modules.

A

[MatthieuDartiailh]

@inventshah provided a minimal reproducer in #137573 (comment)

[AA-Turner]

Missed that, sorry. I'll close this as a duplicate of #137573.