ipython_bug.py

from IPython.kernel import client
from nodes import DummyClass #change to wherever you've put DummyClass


taskclient = client.TaskClient()

cmdstr = "result = task.run()"
task = client.StringTask(cmdstr,
                                 push = dict(task=DummyClass()),
                                 pull = 'result')
tid = taskclient.run(task, block = False)

res = None
while res == None:
    res = taskclient.get_task_result(tid, block = False)

print res

if res.failure:
    res.raise_exception()

ipython_bug_class.py

#must be in PYTHONPATH

class DummyClass(object):
    
    def run(self):
        return self._methodA()
        
    def _methodA(self):
        return self._methodB()
    
    def _methodB(self):
        return self._methodC()
    
    def _methodC(self):
        raise IOError