-The key nubs are stored in KEEPER/I for each 0 <= I < N in the current
-directory; presumably you'll do something sensible with them. A new
-directory $KEYS/keeper/KEEPER is created (it is an error if it already
-exists), containing the key store directories and some metadata meta.
+The key nubs are stored in a safe but temporary place where they can be
+extracted using \`keys keeper-nub'.