Python libraries are usually rock solid. Perl modules in CPAN before that. Now I have been playing with Javascript recently, and that is a whole different story. Unfortunately my JS isn't good enough to improve what has been done.
Recently I had to hack the Django test runner, so I could use a copy of my prod database. I hacked it enough to do what I wanted, but I know that releasing that would probably cause people as many problems as it solved, giving them false hope in a solution that worked on my machine with my setup.
I had initially though it would be something the community would want (having googled around to get a solution), but the fact is, to do it an a quality way (one that I would expect to solve more problems than it creates for the average user) would take significantly longer. I don't wnt to pollute good quality projects like Django with crap hacks. I will however be happy to write a blog post or stack overflow answer explaining what I did and how someone else can do the same - with the full understanding it is a bit of a hack, and may or may not affect.
(I have put in the occasional bug report. Am I being too much of a perfectionist for the open source community, assuming that crap code is not better than no code?)