What steps will reproduce the problem?
(1) Got 404 when open https://ci.chromium.org/p/chromium/builders/luci.chromium.findit/findit_variable/20060

What is the expected result?
Show "Login with google.com account required"
Show 503 or forbidden access, etc. 

What happens instead?
Show 404 which is super confusing

Context: https://bugs.chromium.org/p/chromium/issues/detail?id=890285#c2