There have been significant changes in bogofilter's use of Berkeley
DB.  Bogofilter now uses the Transactional mode to ensure database
integrity.  If you are updating from a bogofilter version older than
0.93.0, you may need to configure your database environment.

If you encounter messages like:

    "Lock table is out of available locks"
or  "Lock table is out of available object entries"

then you need to configure your database environment.  The FAQ has
some information on this problem and file README.db has full details.