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]