Message 177008 - Python tracker

To me, the whole issue is at line ~ 480 in peehole.c in the LOAD_NAME/LOAD_GLOBAL switch case.

This explains the difference between `return` and `return None` as the former is actually compiled to LOAD_CONST. OTOH, `return None` has to pass the optim pass to be changed in LOAD_CONST. The real bug is sometime it doesn't.