3.12.7: gh-113993 backported without subsequent fixes, causing `python3: Objects/unicodeobject.c:15018: intern_common: Assertion `_Py_IsImmortal(r)' failed.`

[mgorny]

Crash report

What happened?

The 49f6beb ("Make interned strings mortal") backport introduced ABI-breaking assertions into 3.12.7. As a result, Rust stable ABI packages are now crashing on assertions, e.g. from uv's cargo test:

          5 │+python3: Objects/unicodeobject.c:15018: intern_common: Assertion `_Py_IsImmortal(r)' failed.
          6 │+python3: Objects/unicodeobject.c:15018: intern_common: Assertion `_Py_IsImmortal(r)' failed.

Backporting 281ffb6 seems to fix the immediate issue but I haven't checked for more regressions.

CPython versions tested on:

3.12

Operating systems tested on:

Linux

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

Python 3.12.7 (main, Oct 1 2024, 21:49:30) [GCC 14.2.1 20240921]

[ZeroIntensity]

Ah, this problem again. assert(_Py_IsImmortal(...)) breaks stable ABI extensions -- we're supposed to use assert(_Py_IsImmortalLoose(...)). IIRC, that PR took a while to backport, so there's a chance that it predated _Py_IsImmortalLoose. cc @encukou

[encukou]

I missed this in the big backport. My apologies :(

[encukou]

I've merged the backport: #124938

[mgorny]

Thank you!