@gpowerf Ouch, that's dreadful - do you know who the pooper was? Am not familiar with how Linux containers work under ChromeOS, but I'd hope it wasn't Linux itself that made the mess.
@stevoooo Linux started asking for a root password where none had been set. I don't know if Debian messed itself up or something happened with the container side... anyway, restoring from a backup worked.
@gpowerf Ouch, that's horrible. I've been using Debian for years and (GNOME desktop aside) I've always found it to be incredibly stable.
I suppose it's another of those life lessons about the backups :-/