Bug report

Bug description:

When using a legacy tracer with PyEval_SetTrace and a function exits with an exception, the arg of the tracer event PyTrace_RETURN should be NULL docs. Currently in 3.12 (& 3.13), the arg is set to the exception value because the PY_UNWIND handler is forwarding its arg to the legacy tracer function.

CPython versions tested on:

3.12

Operating systems tested on:

No response

Linked PRs

• gh-110892: Return NULL for PyTrace_RETURN events caused by an exception #110909