technical_404.html crashes on urlpatterns with include()

[Christian Bahls]

technical_404.html crashes on urlpatterns with include()

Summary

The debug 404 page (technical_404.html) crashes with an AttributeError when urlpatterns contains URLResolver objects created via include().

Description

The template iterates over URL patterns and accesses .name:

{% if forloop.last and pat.name %}[name='{{ pat.name }}']{% endif %}

This fails because .name only exists on URLPattern, not URLResolver. The {% if %} guard does not prevent the crash because Django's template engine evaluates pat.name before checking the conditional.

Exception

AttributeError: 'URLResolver' object has no attribute 'name'

Reproduce

1. Configure urlpatterns with include() without namespace:

   urlpatterns = [
       path("app/", include("myapp.urls")),
   ]
   

2. Set DEBUG=True
3. Request any non-existent URL
4. Debug 404 page crashes instead of rendering

Fix

PR: ​https://github.com/django/django/pull/20533

[Christian Bahls]

i run django 6.0.1 from PyPI in a docker and it crashes
please consider a backport

[Jacob Walls]

Duplicate of #26886, this behavior didn't change recently. Also, it doesn't crash, it just logs this noisy traceback.