pymongo errors aren't propagated properly

[odedfos]

Errors originating from the pymongo driver aren't properly propagated to the application.

For instance, when performing a geospatial query when there is no 2dsphere index on the collection, I get the following error:

File "/project/env/local/lib/python2.7/site-packages/pymongo/cursor.py", line 977, in next
      if len(self.__data) or self._refresh():
File "/project/env/local/lib/python2.7/site-packages/pymongo/cursor.py", line 902, in _refresh
      self.__read_preference))
File "/project/env/local/lib/python2.7/site-packages/pymongo/cursor.py", line 839, in __send_message
      codec_options=self.__codec_options)
File "/project/env/local/lib/python2.7/site-packages/pymongo/helpers.py", line 112, in _unpack_response
      error_object = bson.BSON(response[20:]).decode()
AttributeError: 'module' object has no attribute 'BSON'

When I disable cbson with:
os.environ['MONGOKAT_DISABLE_CBSON'] = "1"

I get the proper error:

  File "/project/env/local/lib/python2.7/site-packages/pymongo/cursor.py", line 977, in next
    if len(self.__data) or self._refresh():
  File "/project/env/local/lib/python2.7/site-packages/pymongo/cursor.py", line 902, in _refresh
    self.__read_preference))
  File "/project/env/local/lib/python2.7/site-packages/pymongo/cursor.py", line 839, in __send_message
    codec_options=self.__codec_options)
  File "/project/env/local/lib/python2.7/site-packages/pymongo/helpers.py", line 122, in _unpack_response
    error_object)
OperationFailure: database error: error processing query: ns=test_test.pl_venue ntoreturn=100
Tree: GEONEAR  field=geolocation maxdist=100 isNearSphere=0
Sort: {}
Proj: {}
 planner returned error: unable to find index for $geoNear query

requirements:
pymongo==3.0.3
mongokat==0.1.4