id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
29718	Document admin template collision backwards incompatibility in Django 2.1	Aymeric Augustin	nobody	"I have a `cupido.Device` Model and a corresponding ModelAdmin with a custom view that renders a template called `admin/cupido/device/search_form.html`.

After upgrading to Django 2.1, the changelist view crashes with a very confusing error:

{{{
NoReverseMatch at /admin/cupido/device/
Reverse for 'app_list' with keyword arguments '{'app_label': ''}' not found. 1 pattern(s) tried: ['admin\\/(?P<app_label>auth|cupido)/$']
}}}

This is because Django now supports overriding `admin/<app_label>/<model_name>/search_form.html` and picks up my template, which breaks because it was written for a completely different purpose. This pitfall — the risk of collision with preexisting templates — could be mentioned in the 2.1 release notes.

Furthermore, the debug view doesn't identify the correct line. It says there's an error at line 11 (see attachment) but I couldn't identify any template in which a line 11 contains a `{% url ... %}` tag that could result in this error. I have no idea what's happening there; I couldn't put together a good bug report for that problem."	Cleanup/optimization	closed	Documentation	2.1	Normal	fixed			Accepted	1	0	0	0	0	0