`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

Empieza con test.test_call.TestRecursion.test_super_deep y reproduce el fallo de segmentación en una compilación free-threading de 3.14.0a4; después, compáralo con 3.14.0a3. Revisa el PR enlazado gh-128958 para conocer la investigación actual; se considera terminado cuando el test ya no produce un fallo de segmentación sin ocultar la regresión subyacente.