Raymond, could you please get the title back? You unintentionally hijacked the issue. The "Document the circumstances where the locals() dict gets updated" is not a describing title for this issue - it is one of the possible action items. I'd prefer to see a separate issue to document the stuff that "blocks" this one. It is quite evident that this action is required, but IMHO there is not enough evidence to conclude that it will be sufficient to close this ticket.

Eric, I need more time to answer your questions.