Crash when formatting exceptions

[tsuraan]

I'm trying to print out the representation of an exception's class, and MissingPy is exploding on me. I'm not sure how to track this down, but the error seems to be repeatable (under ghc-7.4.1 and MissingPy-0.10.5):

Prelude Python.Interpreter Python.Exceptions Python.Types Python.Objects> catchPy (pyRun_SimpleString("raise Exception('foo')")) (\e -> (reprOf $ excType e) >>= putStrLn)
Traceback (most recent call last):
File "", line 1, in
Exception: foo
Segmentation fault