`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

从 test.test_call.TestRecursion.test_super_deep 开始，在 3.14.0a4 的 free-threading 构建中复现 segmentation fault，然后与 3.14.0a3 进行比较。查看链接的 PR gh-128958 以了解当前的调查；完成的标准是测试不再发生 segmentation fault，同时不掩盖底层的 regression。