This package currently has a perpetual postinstall script to keep the database indexed, but doesn't provide for a way to create the initial database during install. I suggest to create another sub-package (perhaps called man-db-index) that simply creates an empty file /var/cache/man-db/index.dat on installation, so that the perpetual install script will trigger. I would prefer if that file was created by a normal postinstall script instead of directly provided in the package since otherwise deinstallation of man-db-index would delete the database.
Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptations for KORG EX-800 and Poly-800MkII V0.9: http://Synth.Stromeko.net/Downloads.html#KorgSDada