While working on http://perltuts.com I had to write a test runner what would test tutorial exercises. It would create a Perl package that uses Test::More than evaluate it, catch the output and return to the caller. This was easy. But than as a good Perl guy I had to test it, actually I had to write a test before writing an implementation, but that's another story! So... I wanted to test it with a Test::Class (uses Test::Builder internally). Needless to say it didn't work, because Test::More is an evil singleton! I had to deploy soon so I had to do something. And I did. I did a very dirty thing and it worked.