Feature or enhancement

Proposal:

cpython's CI should run Undefined Behavior Sanitizer (UBSAN), like it already does for Address Sanitizer (ASAN).

It already has support in configure for this with ./configure --with-undefined-behavior-sanitizer.

This is important for portability, future proofing (keeping CPython working with a range of compilers), and avoiding confusing bug reports later when UB manifests.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-111758: Run UBSan in GitHub Actions #135578