Comment by bsammon

Alternatively, I've found the "Maybe it's a bug. I'll try an make a test case I can report on the mailing list" approach useful at times.

Usually, in the process of reducing my error-generating code down to a simpler case, I find the bug in my logic. I've been fortunate that heisenbugs have been rare.

Once or twice, I have ended up with something to report to the devs. Generally, those were libraries (probably from sourceforge/github) with only a few hundred or less users that did not get a lot of testing.