[halter73]

After going through all that effort to make the test less "fake", I expect tialaramex verified the collision still happened as part of the test.

[tialaramex]

Yes, actually we also verified that all the hashes were exactly what we expected, because we were using this for content based addressing. "The hash has unexpectedly changed" was a fatal build error.

If we wanted to change how the hash is calculated all extant instances of the system need to dump to backups, then be painstakingly restored after updating. Possible, but certainly not something you'd be doing for giggles.