strange problem with multiprocessing

[Neal Becker]

Any idea what this could be about?

Traceback (most recent call last):
  File "run-tests-10111104.py", line 48, in <module>
    results = pool.map (run_test, cases)
  File "/usr/lib64/python2.7/multiprocessing/pool.py", line 199, in map
    return self.map_async(func, iterable, chunksize).get()
  File "/usr/lib64/python2.7/multiprocessing/pool.py", line 491, in get
    raise self._value
ValueError: cannot convert float NaN to integer