Fixing a broken Debian package

Last week I tackled another upgrade of Bugzilla on my Debian server. Unfortunately, I found out the hard way that the package that I tried to install (bugzilla3- was badly broken - I was left with a half-completed installation that simply would not work. I reported the problem but got no response, so I decided to get to the bottom of this and find out what the trouble is. This is not the story of what I found out, but of how I was finally able to fix the problem.