Still randomly getting ignored exceptions on 3.3 and the default
branch, got for example:
Exception TypeError: TypeError("argument of type 'NoneType' is not
iterable",) in <function _removeHandlerRef at 0x7fcbe6014200> ignored

This happens in a threaded application. The root cause is explained in
http://bugs.python.org/issue1722344#msg62078
Instead of building a test case to reproduce the problem, the attached
teardown_module.py script is a contrived example that shows the issue
9501 is not fully fixed. Ignored exceptions appear randomly, so
teardown_module.py must be run in a loop, for example:

    $ while [ 1 ]; do python teardown_module.py; sleep .1; done

The attached patch fix the issue by testing all the globals used in
_removeHandlerRef and teardown_module.py runs fine with this patch
applied.