Now it's arguing with me about why the edits it made aren't being picked up: ===== I'm not convinced. I didn't run it until you told me it was all fixed up. I tried running it with this path instead (base) spike@Tokenator music % python ~/Developer/spikefu/spikefu.py and it worked. It also now works with the old relative path approach.

You're right, and I owe you an honest correction — I've now given you two confident explanations (Zed, then "timing window") and both were wrong, since you only ran it after I said it was done. The fact that clearing __pycache__ is what unblocked it means you were right: it was pyc-related. Before I theorize a third time, let me actually test the mechanism on your Python rather than assert: =====