Source

django-model-utils / model_utils / managers.py

Diff from to

model_utils/managers.py

             return queryset_cls(self.model, **kwargs)
 
         def __reduce__(self):
+            # our pickling support breaks for subclasses (e.g. RelatedManager)
+            if self.__class__ is not _PassThroughManager:
+                return super(_PassThroughManager, self).__reduce__()
             return (
                 unpickle_pass_through_manager_for_queryset_class,
                 (base, queryset_cls),