[1st1]

Pydantic constructs UUIDs by calling the type's tp_new and setting int and is_safe through PyObject_GenericSetAttr. The C UUID implementation made these descriptors read-only, so that construction path fails after #139123.

Add setters for both descriptors, restoring construction through object.__setattr__ and PyObject_GenericSetAttr. Ordinary assignment still raises TypeError, matching the Python UUID implementation. The integer setter validates the value and converts it into a temporary 16-byte, big-endian buffer before updating the UUID, so failed conversions leave the object unchanged. Successful replacement invalidates the cached hash.

Tests cover construction without __init__, subclasses, 128-bit boundary values, integer subclasses, hash invalidation, and rejected assignments preserving the original value and hash.

Validation: the full test_uuid suite passed (165 tests, 22 skipped), including -R 3:3 reference leak checks. A direct PyObject_GenericSetAttr smoke test reproduced Pydantic's construction sequence successfully. Ruff and git diff --check passed.

Refs #139122.

• Issue: Implement UUID functions and type in C #139122

[picnixz]

Ok that's weird: I deleted the file from your branch (and it shows as deleted) but GH is still showing it here. I will wait a bit (or maybe you should force push again). Sorry for the mess though (otherwise LGTM!)