beware 1642

[PowerDiver]

I've been hit by a bug in cave generation in r1642. I don't know how far back it was introduced. The level is occasionally generated with a single boring room, so no corridors, so an infinite loop looking for a place to put rubble.

If you are playing the nightlies, save before stairs or anything else that creates a level. If it fails, you can nuke the process, restart, and do something to change the seed before you try the stairs again.