Test failures on Python 3.13.3 freethreaded

[mgorny]

When testing the newly-added freethreading support, I'm seeing the following test failures:

$ tox -e 3.13t
.pkg: _optional_hooks> python /usr/lib/python3.13/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: get_requires_for_build_sdist> python /usr/lib/python3.13/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: get_requires_for_build_wheel> python /usr/lib/python3.13/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: prepare_metadata_for_build_wheel> python /usr/lib/python3.13/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: build_sdist> python /usr/lib/python3.13/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
3.13t: install_package> python -I -m pip install --force-reinstall --no-deps /tmp/py-setproctitle/.tox/.tmp/package/3/setproctitle-1.3.6.tar.gz
3.13t: commands[0]> pytest
========================================================= test session starts =========================================================
platform linux -- Python 3.13.3, pytest-8.3.5, pluggy-1.5.0
cachedir: .tox/3.13t/.pytest_cache
rootdir: /tmp/py-setproctitle
configfile: pyproject.toml
collected 28 items                                                                                                                    

tests/module_test.py ...                                                                                                        [ 10%]
tests/setproctitle_test.py ...s.........FF.....                                                                                 [ 82%]
tests/setthreadtitle_test.py ...                                                                                                [ 92%]
tests/test_win32.py ss                                                                                                          [100%]

============================================================== FAILURES ===============================================================
____________________________________________________________ test_embedded ____________________________________________________________

pyrun = '/tmp/py-setproctitle/tests/pyrun3.13', spt_directory = '/tmp/py-setproctitle/.tox/3.13t/lib/python3.13t/site-packages'

    @pytest.mark.embedded
    @skip_if_pypy
    @skip_if_macos
    @skip_if_no_proc_cmdline
    def test_embedded(pyrun, spt_directory):
        """Check the module works with embedded Python."""
        rv = run_script(
            f"""
    import sys
    sys.path.insert(0, {spt_directory!r})
    import setproctitle
    setproctitle.setproctitle("Hello, embedded!")
    
    import os
    print(os.getpid())
    print(os.popen("ps -x -o pid,command 2> /dev/null").read())
    """,
            executable=pyrun,
        )
        lines = [line for line in rv.splitlines() if line]
        pid = lines.pop(0)
        pids = dict([r.strip().split(None, 1) for r in lines])
    
        title = _clean_up_title(pids[pid])
>       assert title == "Hello, embedded!"
E       AssertionError: assert '/tmp/py-setp...sts/pyrun3.13' == 'Hello, embedded!'
E         
E         - Hello, embedded!
E         + /tmp/py-setproctitle/tests/pyrun3.13

tests/setproctitle_test.py:362: AssertionError
_______________________________________________________ test_embedded_many_args _______________________________________________________

pyrun = '/tmp/py-setproctitle/tests/pyrun3.13', spt_directory = '/tmp/py-setproctitle/.tox/3.13t/lib/python3.13t/site-packages'

    @pytest.mark.embedded
    @skip_if_pypy
    @skip_if_macos
    @skip_if_no_proc_cmdline
    def test_embedded_many_args(pyrun, spt_directory):
        """Check more complex cmdlines are handled in embedded env too."""
        rv = run_script(
            f"""
    import sys
    sys.path.insert(0, {spt_directory!r})
    import setproctitle
    setproctitle.setproctitle("Hello, embedded!")
    
    import os
    print(os.getpid())
    print(os.popen("ps -x -o pid,command 2> /dev/null").read())
    """,
            executable=pyrun,
            args=" ".join(["foo", "bar", "baz"]),
        )
        lines = [line for line in rv.splitlines() if line]
        pid = lines.pop(0)
        pids = dict([r.strip().split(None, 1) for r in lines])
    
        title = _clean_up_title(pids[pid])
>       assert title == "Hello, embedded!"
E       AssertionError: assert '/tmp/py-setp...3 foo bar baz' == 'Hello, embedded!'
E         
E         - Hello, embedded!
E         + /tmp/py-setproctitle/tests/pyrun3.13 foo bar baz

tests/setproctitle_test.py:390: AssertionError
======================================================= short test summary info =======================================================
FAILED tests/setproctitle_test.py::test_embedded - AssertionError: assert '/tmp/py-setp...sts/pyrun3.13' == 'Hello, embedded!'
FAILED tests/setproctitle_test.py::test_embedded_many_args - AssertionError: assert '/tmp/py-setp...3 foo bar baz' == 'Hello, embedded!'
=============================================== 2 failed, 23 passed, 3 skipped in 1.33s ===============================================
3.13t: exit 1 (1.54 seconds) /tmp/py-setproctitle> pytest pid=266862
  3.13t: FAIL code 1 (5.71=setup[4.17]+cmd[1.54] seconds)
  evaluation failed :( (5.79 seconds)

For comparison, tox -e 3.13 passes. I can reproduce both with 1.3.6 release and 11d5ba7. That said, I have no clue why it passes on CI and not for me. The library is definitely there:

>>> import setproctitle._setproctitle
>>> setproctitle._setproctitle
<module 'setproctitle._setproctitle' from '/tmp/py-setproctitle/.tox/3.13t/lib/python3.13t/site-packages/setproctitle/_setproctitle.cpython-313t-x86_64-linux-gnu.so'>

This is Gentoo Linux amd64.

[dvarrazzo]

No idea. Does the pyrun executable used by the test get built correctly?