ParameterSweep.clear_result() result in error...

[Wrede]

After an error have occurred in the mapper function, a clear_results() is needed after updating the mapper. However after clear_results I get this error each time:

Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/IPython/parallel/controller/hub.py", line 1348, in get_results
matches = self.db.find_records(dict(msg_id={'$in':msg_ids}))
File "/usr/local/lib/python2.7/dist-packages/IPython/parallel/controller/dictdb.py", line 313, in find_records
raise NODATA
KeyError: "NoDB backend doesn't store any data. Start the Controller with a DB backend to enable resubmission / result persistence."

[briandrawert]

I believe your local install of molns needs to be updated. This commit briandrawert/molns@7a42699 is necessary for the new branch of molnsutil to work. You will have to stop and start your controller to propagate this change (but it is not necessary to rebuild the image, I think).