Unhelpful error message: 'tuple index out of range'

[Michael@…]

There's something evidently wrong with my urls.py, but this error message is absolutely no help in sorting it out. Please have it output which tuple it's trying to index. The error message is providing no context, and unlike normal python tracebacks it is not tied to a particular line in my urls.py.

Traceback (most recent call last):

  File "c:\django\django\core\servers\basehttp.py", line 277, in run
    self.result = application(self.environ, self.start_response)

  File "c:\django\django\core\servers\basehttp.py", line 631, in __call__
    return self.application(environ, start_response)

  File "c:\django\django\core\handlers\wsgi.py", line 205, in __call__
    response = self.get_response(request)

  File "c:\django\django\core\handlers\base.py", line 130, in get_response
    callback, param_dict = resolver.resolve500()

  File "c:\django\django\core\urlresolvers.py", line 275, in resolve500
    return self._resolve_special('500')

  File "c:\django\django\core\urlresolvers.py", line 264, in _resolve_special
    callback = getattr(self.urlconf_module, 'handler%s' % view_type)

  File "c:\django\django\core\urlresolvers.py", line 255, in _get_urlconf_module
    raise ImproperlyConfigured, "Error while importing URLconf %r: %s" % (self.urlconf_name, e)

ImproperlyConfigured: Error while importing URLconf 'reports.urls': tuple index out of range

Here's the urls.py that is evidently not acceptable, but I cannot see which tuple of tuples of tuples it is trying to index and failing on:

from django.conf.urls.defaults import *
import views as views
import settings

urlpatterns = patterns('',
    # Example:
    # (r'^reports/', include('reports.foo.urls')),
    (r'^$', views.home_page),
)

if settings.DEBUG:
    urlpatterns += patterns('',
        (r'^images/(?P<path>.*)$', 'django.views.static.serve',
         {'document_root': 'c:/projects/djcode/reports/images'}),
        (r'^css/(?P<path>.*)$', 'django.views.static.serve',
         {'document_root': 'c:/projects/djcode/reports/css'}),
    )

[Thomas Güttler]

I can't reproduce your exception, but I know the problem. Up to now the original exception is lost.
I wrote a patch which passes the exception up to the debug view.

Please test and leave a comment.

[John-Scott Atlakson]

I'm not sure why they are catching all exceptions on __import__() only to instead raise a generic ImproperlyConfigured exception that usually is not of any help when resolving whatever the error actually is. In my experience, I've never seen this error because of a borked urls.py, it's almost always been something messed up in a view.

I simply removed the try/except wrapping self._urlconf_module = __import__(self.urlconf_name, {}, {}, ['']) to let the actual exceptions percolate up, rather than try to hack informativeness into the generic catch-all exception. If you run into an actual import error (as the code comment suggests they are guarding against), why not just let the ImportError bubble up? All other errors need to be revealed so we can see why resolving urls bombs so mysteriously. I'll attach a quick patch, just for completeness' sake.

Closing this as a duplicate of #7524 (even if this ticket is older and had the patch earlier) as the other ticket got triaged ...