Can I ask why you think a 404 would be better here?  Is the issue the endless loading spinner as opposed to a proper error message?

Yes, the loading spinner sets the expectation that something will appear which is not the case.

Showing nothing does not really give the user a feedback what has gone wrong. A 404 is a quite specific error message and Chromium devs should be able to understand it.

This Cl refers to this issue: https://chrome-internal-review.googlesource.com/c/infra/infra_internal/+/457652

Staging: https://6825-a82fd63-tainted-odeedee-dot-chromiumdash-staging.googleplex.com/commit/sdfb

Thanks!

I think we should return a real 404.

I looked at other tools to see what they do:

 - Gerrit returns a "fake" 404 like odeedee@ proposes: https://chrome-internal-review.googlesource.com/c/infra/infra_internal/+/458258

 - GoB returns a real 404: https://chromium.googlesource.com/chromium/src.git/+/5fb1fe0ef0434casdasd24a0b1c598840879f04a3

Since no user should really get into this state if they're just following the UI and not hacking URLs, if hablich@ feels like we should serve a real 404, I am OK with that, but we need to log the hell out of it (to ensure we fix any systemic issues that may occur).  My preference is more like what odeedee@ proposes FWIW.

Monorail: states the issue doesn't exist, https://bugs.chromium.org/p/chromium/issues/detail?id=11111111

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infra/infra_internal/+/2d66e9b972381fec23cbe9bdf6d16164190130ec

commit 2d66e9b972381fec23cbe9bdf6d16164190130ec
Author: odeedee <odeedee@google.com>
Date: Fri Sep 22 14:35:10 2017

Re #6: Fake 404 it is than.