Aha - forgot. The new python pipeline doesn't actually do

[cache]

writes, it just uses local invalidation. @astonishing-jelly-60479 I think this is worth filing an issue. The crux looks like its here: https://github.com/jsirois/pants/blob/master/src/python/pants/backend/python/tasks2/resolve_requirements_task_base.py#L43-L50