Python-3.11 assertion failed during testing

[orlitzky]

Originally reported in https://bugs.gentoo.org/923000 where the full build log is available.

Summary:

Assertion failed: (PyObject **)frame + frame->f_code->co_nlocalsplus + frame->f_code->co_stacksize + FRAME_SPECIALS_SIZE == tstate->datastack_top (Python/ceval.c: _PyEvalFrameClearAndPop: 6401)

That happened with python-3.11.7, while the same test suite passed under python-3.10.13. The tinderbox that discovered the problem is running musl libc in case that matters.

[mgorny]

I can reproduce the same crash on a glibc system. That said, the bug seems to be in cysignals:

python3.11: Python/ceval.c:6401: _PyEvalFrameClearAndPop: Assertion `(PyObject **)frame + frame->f_code->co_nlocalsplus + frame->f_code
->co_stacksize + FRAME_SPECIALS_SIZE == tstate->datastack_top' failed.
------------------------------------------------------------------------
/usr/lib/python3.11/site-packages/cysignals/signals.cpython-311-x86_64-linux-gnu.so(+0x89db)[0x7f368ccff9db]
/usr/lib/python3.11/site-packages/cysignals/signals.cpython-311-x86_64-linux-gnu.so(+0x8a9f)[0x7f368ccffa9f]
/usr/lib/python3.11/site-packages/cysignals/signals.cpython-311-x86_64-linux-gnu.so(+0xbb4d)[0x7f368cd02b4d]
/usr/lib64/libc.so.6(+0x3c9d0)[0x7f368dc4b9d0]
/usr/lib64/libc.so.6(+0x8e2bc)[0x7f368dc9d2bc]
/usr/lib64/libc.so.6(gsignal+0x16)[0x7f368dc4b926]
/usr/lib64/libc.so.6(abort+0xd7)[0x7f368dc338f7]
/usr/lib64/libc.so.6(+0x2481b)[0x7f368dc3381b]
/usr/lib64/libc.so.6(+0x34f26)[0x7f368dc43f26]
/usr/lib64/libpython3.11.so.1.0(+0x10bc17)[0x7f368df0bc17]
/usr/lib64/libpython3.11.so.1.0(+0x1ccf57)[0x7f368dfccf57]
/usr/lib64/libpython3.11.so.1.0(PyEval_EvalCode+0xa7)[0x7f368e05cbd7]
/usr/lib64/libpython3.11.so.1.0(+0x272650)[0x7f368e072650]
/usr/lib64/libpython3.11.so.1.0(_PyEval_EvalFrameDefault+0x481f)[0x7f368dfd6d6f]
/usr/lib64/libpython3.11.so.1.0(+0x1ccf30)[0x7f368dfccf30]
/usr/lib64/libpython3.11.so.1.0(PyEval_EvalCode+0xa7)[0x7f368e05cbd7]
/usr/lib64/libpython3.11.so.1.0(+0x2771d3)[0x7f368e0771d3]
/usr/lib64/libpython3.11.so.1.0(+0x272fca)[0x7f368e072fca]
/usr/lib64/libpython3.11.so.1.0(+0x2868e1)[0x7f368e0868e1]
/usr/lib64/libpython3.11.so.1.0(_PyRun_SimpleFileObject+0x1b2)[0x7f368e086662]
/usr/lib64/libpython3.11.so.1.0(_PyRun_AnyFileObject+0x44)[0x7f368e086464]
/usr/lib64/libpython3.11.so.1.0(Py_RunMain+0x353)[0x7f368e085803]
/usr/lib64/libpython3.11.so.1.0(Py_BytesMain+0x37)[0x7f368e04f477]
/usr/lib64/libc.so.6(+0x26350)[0x7f368dc35350]
/usr/lib64/libc.so.6(__libc_start_main+0x89)[0x7f368dc35409]
python3.11(_start+0x21)[0x561d134ee071]