id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
23182	squashmigrations having trouble with auth.User foreign key	wkschwartz@…	nobody	"Django 1.7rc2 on SQLite and Python 3.4. I'm trying to use `squashmigrations`. It broke, even with `--no-optimize`. The documentation said to report bugs.

My app `myapp` has a model `MyModel` with a couple foreign keys to `django.contrib.auth.User` (yes, `auth` is in my `INSTALLED_APPS`, despite what the stack trace below says; notably everything was working fine before squashing):

{{{#!python
from django.contrib.auth.models import User
from django.db.models import Model, ForeignKey

class MyModel(Model):
    creator = ForeignKey(User, related_name='mymodel_creator_set')
    modifier = ForeignKey(User, related_name='mymodel_modifier_set')
    # ... and then a bunch of business logic...
}}}

I have a few other models with foreign keys to `User`, but that's the one that shows up in the stack trace.

I had accumulated 18 migrations, which were slowing down my tests (the migrations always run at the start of `migrations.py test`, at least when developing on SQLite). So I ran

{{{
#!bash
(venv) $ ./manage.py squashmigrations myapp 0018
}}}

Then when I ran

{{{
#!bash
(venv) $ rm db.sqlite3 && ./manage.py migrate
}}}

I got the stack trace below. When I deleted the squashed migration and reran it with `--no-optimize`, I got exactly the same stack trace.

{{{
(venv3) $ rm db.sqlite3 && ./manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions, myapp
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying sessions.0001_initial... OK
  Applying myapp.0001_squashed_0018_<redacted>...Traceback (most recent call last):
  File "".../django/apps/registry.py"", line 136, in get_app_config
    return self.app_configs[app_label]
KeyError: 'auth'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "".../django/db/migrations/state.py"", line 79, in render
    model = self.apps.get_model(lookup_model[0], lookup_model[1])
  File "".../django/apps/registry.py"", line 190, in get_model
    return self.get_app_config(app_label).get_model(model_name.lower())
  File "".../django/apps/registry.py"", line 138, in get_app_config
    raise LookupError(""No installed app with label '%s'."" % app_label)
LookupError: No installed app with label 'auth'.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ""./manage.py"", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "".../django/core/management/__init__.py"", line 385, in execute_from_command_line
    utility.execute()
  File "".../django/core/management/__init__.py"", line 377, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "".../django/core/management/base.py"", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "".../django/core/management/base.py"", line 337, in execute
    output = self.handle(*args, **options)
  File "".../django/core/management/commands/migrate.py"", line 160, in handle
    executor.migrate(targets, plan, fake=options.get(""fake"", False))
  File "".../django/db/migrations/executor.py"", line 62, in migrate
    self.apply_migration(migration, fake=fake)
  File "".../django/db/migrations/executor.py"", line 90, in apply_migration
    if self.detect_soft_applied(migration):
  File "".../django/db/migrations/executor.py"", line 134, in detect_soft_applied
    apps = project_state.render()
  File "".../django/db/migrations/state.py"", line 89, in render
    model=lookup_model,
ValueError: Lookup failed for model referenced by field myapp.MyModel.modifier: auth.User
}}}"	Bug	closed	Migrations	1.7-rc-2	Normal	needsinfo	migrations, squashmigrations		Unreviewed	0	0	0	0	0	0