Named urls are URLs defined in your urlconf that have named views. The
contrib auth app, although it provides a bunch of views, does not
automatically install any of them at any URLs, hence this would fail.
If you include the login view in one of your urlconfs, it will not
have the 'auth' app label, it will have whatever name you decide to
give it.
Cheers
Tom
PS: The fully qualified view name may have worked -
"django.contrib.auth.views.login". There is a function at
"django.contrib.auth.login", but that function is used to actually log
users in, not to present a login form and process it.