Handling of Django >= 1.5 custom user model broken in 0001_initial.py

[ramiro]

Commit f4ea1fd introduced compatibility with the new custom user. Later fixed to be compatible with Django < 1.5 in b4f7e0c.

But one problem is that it blindly puts the custom user model in the frozen ORM section of the migration and so the final description of the model is one pointing to the developer's custom user model but that has the fields of django.contrib.auth.models.User (!):

django-reversion/src/reversion/migrations/0001_initial.py

Lines 62 to 77 in e956571

	"%s.%s" % (User._meta.app_label, User._meta.module_name): {
	'Meta': {'object_name': User.__name__, "db_table": "'%s'" % User._meta.db_table},
	'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
	'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
	'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
	'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
	'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
	'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
	'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
	'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
	'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
	'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
	'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
	'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
	'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
	},

    "%s.%s" % (User._meta.app_label, User._meta.module_name): {
        'Meta': {'object_name': User.__name__, "db_table": "'%s'" % User._meta.db_table},
        'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
        'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
        'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
        'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
        'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
        'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
        'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
        'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
        'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
        'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
        'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
        'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
        'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
      },

This is wrong. Unfortunately I don't have a solution and I'm not sure if there is actually one.

Found this when researching a solution for a

ImproperlyConfigured: AUTH_USER_MODEL refers to model 'app.User' that has not been installed

error when running the migrations for a non-trivial project that included django-reversion. The error is triggered by the import-time call to get_user_model() at the top of the migration.

When South reloads the migrations (among them django-reversion's) that function fails reporting it can't find the custom user model although it's actually on the Django app/model cache, which would suggest a circular import problem.

IMHO there It would be good if a solution similar to 798cc8b could be applied to the migration file and so avoid having an import-time get_user_model() call.

See also:

dabapps/django-user-roles#6
https://github.com/caffeinehit/django-oauth2-provider/pull/18/files

But that is another issue that will be possibly reason for another ticket.

[etianen]

AAAAAAAAAAAAARG!!!!!

When I saw how django had implemented the custom user model, I had a slight sense of doom, like this was going to be a change that had consequences. I guess this is one of them.

Could it be that a custom user model simply breaks migrations?

This issue is obviously related to #263

[etianen]

Oh, it gets worse. All the subsequent migrations have hardcoded user fields.

This blog post http://kevindias.com/writing/django-custom-user-models-south-and-reusable-apps/ seems to be indicating that you can dynamically adapt to the user model's fields, and only need to specify the pk and meta. This seems a bit dodgy to me, as if all the fields are not needed, why does south include them.

In fact, more generally, if south goes to all the effort of serializing the complete state of your models, doesn't attempting to generate this at runtime entirely defeat what south is trying to do here?

[etianen]

This issue seems to have been fixed in South 0.8.4