`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

從 test.test_call.TestRecursion.test_super_deep 開始，在 3.14.0a4 的 free-threading 建置中重現 segmentation fault，然後與 3.14.0a3 比較。檢視連結的 PR gh-128958 以了解目前的調查；完成的條件是測試不再發生 segmentation fault，同時不掩蓋底層的 regression。