Incorrect duplicate app message shown when no duplicates found

[Ross Crawford-d'Heureuse]

​https://github.com/django/django/pull/4476

Details of this bug are in the ticket but over view is

I have an app with construct: project_name.apps.core

Consistently got: when running tests

django.core.exceptions.ImproperlyConfigured: Application labels aren't unique, duplicates: core

Despite absolutely no chance of it being duplicate;

print of apps form within registry.py

('project_name.apps.v2_api', 'project_name.apps.v1_api', 'project_name.apps.applications', 'project_name.apps.backend', 'project_name.apps.core', 'project_name.apps.tools', 'project_name.apps.me', 'project_name.apps.brand', 'project_name.apps.workorder', 'project_name.apps.batch', 'project_name.apps.printer', 'project_name.apps.scan', 'project_name.apps.code', 'project_name.apps.dash', 'project_name.apps.role_permission')

Considered it being a conflict with django.core (but seems not to be the case)

Am using a custom test runner

class AppTestRunner(DiscoverRunner):
    def build_suite(self, test_labels, *args, **kwargs):
        # not args passed in
        if not test_labels:
            test_labels = settings.PROJECT_APPS

        return super(AppTestRunner, self).build_suite(test_labels, *args, **kwargs)

As you can see the runner runs test tests from ONLY the project and not the dango/helper app test cases

I noticed there has been a very recent refactor (march) of the registry; which is what prompted the investigation as I have had a 1.7 merge branch for this project for some time and the tests have always run with no issue. I recently re installed django (1, 7, 5, 'final', 0) and this error started happening.

I hope the fix makes sense.

[Tim Graham]

Can you upload a sample project or tell us how we can reproduce this? It seems like you might have an issue in your project as I don't understand why the proposed change needs to be made in Django.

[Ross Crawford-d'Heureuse]

Hi Tim,

I have described and documented the issue in both the ticket and the PR.

I also thought it to be a bug within my project but after extensive investigation its actually not.

In a custom testRunner (extending the default django runner in runner.py) if I inject a tuple of JUST my projects apps the duplicate error arises.

Please review the PR at: ​https://github.com/django/django/pull/4476

Regards
Ross

[Tim Graham]

I tried to reproduce it with the project structure you described, but wasn't having any luck. Is it only an issue with the custom test runner? I didn't try adding that.

[Ross Crawford-d'Heureuse]

Hi there app setup and test runner below.

`
DJANGO_APPS = (

'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',

)

PROJECT_APPS = (

'my_project.apps.v2_api',
'my_project.apps.v1_api',
'my_project.apps.applications',
'my_project.apps.backend',
'my_project.apps.core',
'my_project.apps.tools',
'my_project.apps.me',
'my_project.apps.brand',
'my_project.apps.workorder',
'my_project.apps.batch',
'my_project.apps.printer',
'my_project.apps.scan',
'my_project.apps.code',
'my_project.apps.dash',
'my_project.apps.role_permission',

)

HELPER_APPS = (

'pipeline',
'registration',
'password_reset',
'django_extensions',
'raven.contrib.django.raven_compat',

'parsley',
'corsheaders',
'crispy_forms',
'rest_framework',

)

INSTALLED_APPS = DJANGO_APPS + PROJECT_APPS + HELPER_APPS
`

`
from django.test.runner import DiscoverRunner

class AppTestRunner(DiscoverRunner):

def build_suite(self, test_labels, *args, kwargs):

# not args passed in
if not test_labels:

test_labels = settings.PROJECT_APPS

return super(AppTestRunner, self).build_suite(test_labels, *args, kwargs)

`

[Tim Graham]

Unfortunately, I still can't reproduce it with those details. Could you try putting together a minimal project that reproduces the error that we could download? A regression test for Django's test suite to complement your patch might be fine too.

[Ross Crawford-d'Heureuse]

Ill try allocate some time for it! :) thanks

[Ross Crawford-d'Heureuse]

Ok, so this is very strange. I've re-installed django 1.7 (not change to version tho) aaaand its working.

have been running clean_pyc as well as custom make clean command that looks for pyc files.

..

I guess the bug is invalid.. I apologise for wasting time. And thank you for your efforts to reproduce.