Possibly related to 729889 (*dbm backends don't lock on
commit)

Roundup has not once ever removed a db/lock file, and
this interferes with my incoming email processing. As
far as I can tell, the lock file probably should go
away if no process is actively altering the database. 

Specifically, a sendmail alias triggers roundup-mailgw
to run when a new message arrives, and this fails
because there's already a lock file with the PID of
roundup-server in it. I am able to successfully receive
a new message if I do the following: remove the
lockfile, start roundup-server, send an email, and
remove db/lock again. But if I don't remove db/lock
myself, email will bounce or the web interface will error.

I am interested in workarounds as well as proper
solutions, as I wish to demo roundup (with email) asap.