Django 2.0 Warning: use_for_related_fields is deprecated

[clokep]

Problem

Using the InheritanceManager on a class causes the following warning:

/usr/local/venv/local/lib/python2.7/site-packages/django/db/models/fields/related_descriptors.py:157: RemovedInDjango20Warning: use_for_related_fields is deprecated, instead set Meta.base_manager_name on 'my_app.MyModel'.
  qs = self.get_queryset(instance=instance)

This seems to be used in a couple of places:

• InheritanceManagerMixin
• QueryManagerMixin

I'm not really sure of the ramifications of just removing this vs. using Meta.base_manager_name, etc. I know there's some special things done with the first Manager found on a Django Model class.

Environment

• Django Model Utils version: 3.0.0
• Django version: 1.11.5
• Python version: 2.7.6

[tony]

We need a game plan for this then. 😄 2.0 was released yesterday

[tony]

Possibly related:

• Django 1.10 default manager not MultilingualManager for model inheriting abstract class with a manager defined on objects (leading to AttributeError: 'QuerySet' object has no attribute 'rewrite') deschler/django-modeltranslation#389
• Fix M2M and inherited managers deschler/django-modeltranslation#431

More: https://docs.djangoproject.com/en/2.0/releases/1.10/#manager-use-for-related-fields-and-inheritance-changes

[tony]

More lore:

django/django@ed0ff91

Old API:

class CustomManager(models.Model):  # (sic, pretty sure they meant models.Manager)
    use_for_related_fields = True

class Model(models.Model):
    custom_manager = CustomManager()

New API:

class Model(models.Model):
    custom_manager = CustomManager()

    class Meta:
        base_manager_name = 'custom_manager'

[bahendri]

Seems like this issue should be closed in light of c4d7212.

(In my app, pytest threw this deprecation warning and a quick read seemed to suggest the problem was in this library but I later realized it was my app's fault. If this ticket had been marked closed I might have realized my mistake sooner.)