`test_call.test_super_deep` started segfaulting with 3.14.0a4 freethreading

Crash report

What happened?

test_super_deep (test.test_call.TestRecursion.test_super_deep) ... Fatal Python error: Segmentation fault

The test passes with a3 but segfaults with a4 — so I'm guessing stack frames grew or something. Not sure if this is the kind of regression in code that needs to be fixed, or merely recursion limit needs to be lowered.

This is Gentoo Linux amd64, CPython built with LTO + PGO, CFLAGS are -march=znver2 --param=l1-cache-size=32 --param=l1-cache-line-size=64 -O2 -pipe -frecord-gcc-switches.

Full log: dev-lang:python-3.14.0_alpha4-r100:20250117-163521.txt

CPython versions tested on:

3.14

Operating systems tested on:

Linux

Output from running 'python -VV' on the command line:

Python 3.14.0a4 experimental free-threading build (main, Jan 17 2025, 17:46:22) [GCC 14.2.1 20241221]

Linked PRs

• gh-128958

Comece com test.test_call.TestRecursion.test_super_deep e reproduza o segmentation fault em um build free-threading do 3.14.0a4; depois, compare-o com o 3.14.0a3. Revise o PR vinculado gh-128958 para acompanhar a investigação atual; considera-se concluído quando o teste não causar mais segmentation fault sem mascarar a regressão subjacente.