Fixed #22922: Better error message for InvalidBasesError.

                    except InvalidBasesError:

                        new_unrendered_models.append(model)

                if len(new_unrendered_models) == len(unrendered_models):

                    raise InvalidBasesError("Cannot resolve bases for %r" % new_unrendered_models)

                    raise InvalidBasesError("Cannot resolve bases for %r\nThis can happen if you are inheriting models from an app with migrations (e.g. contrib.auth)\n in an app with no migrations; see https://docs.djangoproject.com/en/1.7/topics/migrations/#dependencies for more" % new_unrendered_models)

                unrendered_models = new_unrendered_models

            # make sure apps has no dangling references

            if self.apps._pending_lookups: