Commit fc974313 authored by Andrew Godwin's avatar Andrew Godwin
Browse files

Fixed #22563: Better error message when trying to change AUTH_USER_MODEL 

You're not allowed to do this after you've made migrations; see ticket
for more details.
parent a2e3c969

django/db/migrations/state.py

+14 −3
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ from django.apps.registry import Apps, apps as global_apps 
from django.db import models

from django.db.models.options import DEFAULT_NAMES, normalize_together

from django.db.models.fields.related import do_pending_lookups

from django.conf import settings

from django.utils import six

from django.utils.encoding import force_text

from django.utils.module_loading import import_string
@@ -74,13 +75,23 @@ class ProjectState(object): 
                    try:

                        model = self.apps.get_model(lookup_model[0], lookup_model[1])

                    except LookupError:

                        # If the lookup failed to something that looks like AUTH_USER_MODEL,

                        # give a better error message about how you can't change it (#22563)

                        extra_message = ""

                        if "%s.%s" % (lookup_model[0], lookup_model[1]) == settings.AUTH_USER_MODEL:

                            extra_message = (

                                "\nThe missing model matches AUTH_USER_MODEL; if you've changed the value of this" +

                                "\nsetting after making a migration, be aware that this is not supported. If you" +

                                "\nchange AUTH_USER_MODEL you must delete and recreate migrations for its app."

                            )

                        # Raise an error with a best-effort helpful message

                        # (only for the first issue). Error message should look like:

                        # "ValueError: Lookup failed for model referenced by

                        # field migrations.Book.author: migrations.Author"

                        raise ValueError("Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}".format(

                        raise ValueError("Lookup failed for model referenced by field {field}: {model[0]}.{model[1]}{extra_message}".format(

                            field = operations[0][1],

                            model=lookup_model

                            model = lookup_model,

                            extra_message = extra_message,

                        ))

                    else:

                        do_pending_lookups(model)