ImportError: No module named urls only in cerely task caused by tags in rendered template

[Andrey inte]

The site works ok, but when a celery task is called which renderes template for EmailMultiAlternatives, I get ImportError: No module named urls. If I comment out just one app in settings.py (modal_announcements), it works. The app itself runs ok in the site. This is the urls.py (which could not be found, thoght it apparently exists):

from django.conf.urls import patterns, url
from mezzanine.conf import settings
from modal_announcements.views import announcement

urlpatterns = patterns('',
url("^announcement/(?P<pk>.*)%s$" % ("/" if settings.APPEND_SLASH else ""), announcement,
name='announcement')
)
here are the project's urls:

if settings.USE_MODELTRANSLATION:
urlpatterns += patterns('',
url('^i18n/$', 'django.views.i18n.set_language', name='set_language'),
url(r'^robots\.txt$', TemplateView.as_view(template_name='robots.txt',
content_type='text/plain')),

url(r'^chaining/', include('smart_selects.urls')),
)

urlpatterns += i18n_patterns("",
url("^$", home, name='home'),
url(r'^inliner$',
inliner, name='inliner'),
url(r'^autocomplete/', include('autocomplete_light.urls')),
("^orders/",
include("orders.urls", namespace="orders")),
("^shop/",
include("shop.urls", namespace="shop")),
("^programs/",
include("programs.urls", namespace="programs")),
("^prices/",
include("prices.urls", namespace="prices")),
("^tour/", include("tour.urls", namespace="tour")),
("^misc/", include("misc.urls", namespace="misc")),
**("^announcements/", include("modal_announcements.urls", namespace="announcements")),**
("^%s/" %
settings.EVENT_SLUG, include("mezzanine_agenda.urls")),
# ``mezzanine.urls``.
("^", include("mezzanine.urls")),

)


urlpatterns += patterns('',
url('', include('social.apps.django_app.urls', namespace='social')),
)
# Adds ``STATIC_URL`` to the context of error pages, so that error
# pages can use JS, CSS and images.
handler404 = "mezzanine.core.views.page_not_found"
handler500 = "mezzanine.core.views.server_error"

if settings.DEBUG:
import debug_toolbar
urlpatterns += patterns('',
url(r'^__debug__/', include(debug_toolbar.urls)),
)
traceback:

[2017-10-22 01:43:47,493: INFO/MainProcess] Received task: send_mail_template_task[abb16580-9037-4bd9-9f5c-75f85e6a51b4]
[2017-10-22 01:43:47,576: ERROR/ForkPoolWorker-1] Task send_mail_template_task[abb16580-9037-4bd9-9f5c-75f85e6a51b4] raised unexpected: ImportError('No module named urls',) Traceback (most recent call last): File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/celery/app/trace.py", line 374, in trace_task R = retval = fun(*args, **kwargs) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/celery/app/trace.py", line 629, in protected_call return self.run(*args, **kwargs) File "/home/andy/stable/inte-production/misc/tasks.py", line 14, in send_mail_template_task headers=None) File "/home/andy/stable/inte-production/misc/utils.py", line 277, in send_mail_template msg.attach_alternative(t.render(context),"text/html") File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/template/backends/django.py", line 74, in render return self.template.render(context) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/template/base.py", line 210, in render return self._render(context) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/template/base.py", line 202, in _render return self.nodelist.render(context) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/template/base.py", line 905, in render bit = self.render_node(node, context) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/template/debug.py", line 79, in render_node return node.render(context) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/template/defaulttags.py", line 493, in render url = reverse(view_name, args=args, kwargs=kwargs, current_app=current_app) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 578, in reverse return force_text(iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs))) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 432, in _reverse_with_prefix self._populate() File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 284, in _populate for pattern in reversed(self.url_patterns): File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 401, in url_patterns patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module) File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/core/urlresolvers.py", line 395, in urlconf_module self._urlconf_module = import_module(self.urlconf_name) File "/usr/lib/python2.7/importlib/init.py", line 37, in import_module import(name) File "/home/andy/stable/inte-production/inte/urls.py", line 273, in ("^announcements/", include("modal_announcements.urls", namespace="announcements")), File "/home/andy/.virtualenvs/stable/local/lib/python2.7/site-packages/django/conf/urls/init.py", line 33, in include urlconf_module = import_module(urlconf_module) File "/usr/lib/python2.7/importlib/init.py", line 37, in import_module import(name) ImportError: No module named urls

[Andrey inte]

Found the error:

I installed modal_announcements module Looong ago; since I wanted to modify it, I then copied the code to my project and adopted it as needed; it did not give me errors.
But after installing celery it somehow picked the old modal_announcement's urls (or views, or whatever...) from .virtualenv instead of my project and exposed the error to me in this tricky way. Took me ages to figure out!

Morale: clear up properly!