From a bug report, he was running blind while wielding scissors--
I mean Excalibur--and stopped for no apparent reason. The autosearch
capability conferred by that artifact (also by ring of searching, or for
some roles or races once they reach a particular level) had found a secret
door and changed it into a normal door, but since he couldn't see at the
time his map display wasn't updated to show that. This makes the map show
such things even if blind, and also gives a message that the search found
something.
fdf037a89f