404 page does not display stack trace when Resolver404 is raised from a view

[Grzegorz Nosek]

Related to #18373, the 404 error page served when django.core.urlresolvers.resolve() fails does not contain the exception stack trace, which makes finding the failing call unnecessarily difficult.

When the resolve() call fails in a view, the error should actually be 500 (it's not the user's fault), but for backwards compatibility the response code will have to remain 404 (as discussed with Honza Kral last year).

[AeroNotix]

Hi,

What kind of useful information could you gain from a 404 page with a stacktrace? If you're explicitly creating a 404 exception then you want that to happen.

Could you convince this list of the usefulness in changing this behaviour, please?

[Grzegorz Nosek]

See #18373 for the use case.

If you're calling resolve('/some-url') that fails, you're not raising an Http404 explicitly. It's just a function call that fails, just like the ORM or whatever.

I agree that manually raised Http404s should not trigger the stack trace and this ticket is not about it. It's just about treating exceptions from resolve() failure just like every other exception.

IMO, the right thing to do is:

• Failing to resolve a URL from Django core -> no stack trace
• Raising Http404 from a view -> no stack trace
• Failing to resolve a URL from a view -> stack trace (and arguably 500 response code but there's backwards compatibility to worry about)