raise error if there is unsupported extrastuff
@@ -551,6 +551,8 @@ class BaseQueryWrapper(BaseWrapper):
result = list(chain(*(instances.values() for instances in objs_by_pk.values())))
break
+ else:
+ raise NotImplementedError('Cannot do extra() for '+extra)
obj._result_cache = result
obj._prefetch_done = False
