I ran across this exception again today during some reading - and when I first hit it some time ago, I gave it the label of "best python error" (and put it in a bugzilla quip list).
TypeError: Error when calling the metaclass bases
metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases
Every time I read this error, my brain convulses and I suddenly find that it's 3 hours later and I'm not wearing pants.
Seriously: this error could be better done as:
TypeError: You're doomed!
1> Open the chest
2> back out of the room slowly
3> attack the ogre
Of course, I'm being sarcastic for those of you with a broken laugh-o-meter.
I just thought about something - what if you made error messages "realer" like:
IOError: you can not access that thingie right now, it's either not on disk, unavailable - or your stupid USB disk powered off again nubcakes
MemoryError: How in the hell did you do this in a language with GC? Stop it. STOP. OH GOD IT BUR (oomkill from kernel)