Is it possible that a recent docker upgrade messes things up again?
Upgraded docker-ce as part of an overall update of the underlying Debian system earlier on, and now supervisor won’t set up anymore.
To verify, I did the same on a backup system I have and the exact same thing happened.
Reading through this thread and some others, it appears that similar things have happened in the past…
Running suoervised on Debian Bookworm on an Intel nuc 8.