Django staticfiles not found on Heroku (with whitenoise)
<p>This question seems to be asked several time but I can not fix it. </p>

<p>I deployed a django app on production with <code>DEBUG = False</code>. I set my <code>allowed_host</code>. 
I used <code>{% load static from staticfiles %}</code> to load static files. I exactly write the settings sugested by Heroku doc : </p>

<pre><code>BASE_DIR = os.path.dirname(os.path.dirname(__file__))
PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))

STATIC_ROOT = os.path.join(PROJECT_ROOT, 'staticfiles')
STATIC_URL = '/static/'

STATICFILES_DIRS = (
    os.path.join(PROJECT_ROOT, 'static'),
)

STATICFILES_STORAGE = 'whitenoise.django.GzipManifestStaticFilesStorage'
</code></pre>

<p>BUT I got an error 500. And got this traceback (by mail)</p>

<pre><code>...
`cache_name = self.clean_name(self.hashed_name(name))
 File "/app/.heroku/python/lib/python3.5/site-    packages/django/contrib/staticfiles/storage.py", line 94, in hashed_name (clean_name, self))
...
ValueError: The file ‘app/css/font.css’ could not be found with &lt;whitenoise.django.GzipManifestStaticFilesStorage object at 0x7febf600a7f0&gt;.`
</code></pre>

<p>When I run <code>heroku run python manage.py collectstatic --noinput</code> 
All seems ok :</p>

<p><code>276 static files copied to '/app/annuaire/staticfiles', 276 post-processed.</code></p>

<p>Does anyone have an idea to help me, please ?</p>

<p>Thanks</p>

<p>EDIT : </p>

<pre><code>annuaire
|-- /annuaire
|-- -- /settings.py
|-- /app
|-- -- /static/...`
</code></pre>

<p>wsgi.py</p>

<pre><code>from django.core.wsgi import get_wsgi_application
from whitenoise.django import DjangoWhiteNoise


application = get_wsgi_application()
application = DjangoWhiteNoise(application)
</code></pre>