Error: `[Internal bug] Invalid ref dates`

[polwel]

I just saw this error:

[Internal bug] Invalid ref dates: refs/heads/<thebranch> 2026-07-21 07:48:42 +0000 != refs/heads/<thebranch> 2026-07-21 07:25:05 +0000

For what it's worth, I have started playing with jj, so it is not unlikely that jj is messing with the git repo's state in a way that upsets Fork.
(I would be very surprised if jj actually left the repo in an inconsistent state; I rather think this is a Fork issue.)

Let me know what additional data I can provide.