As of bug 1309733, we load resource://devtools/client/shared/widgets/widgets.css which doesn't exist. Julian, can you clarify why you changed this from the existing chrome:// URL and check if anything is going to break if we unbreak the URL?

Sorry I missed that! I don't there is any good reason. I probably wanted to migrate the css to be loaded as a resource file, but it didn't make it in the final patch. The only rules impacting the inspector contained in this css are: > .breadcrumbs-widget-item { > direction: ltr; > } > > .breadcrumbs-widget-item { > -moz-user-focus: normal; > } The first rule will actually break the RTL display of the breadcrumbs in the inspector so I'd like to avoid it. I think we should just stop loading this stylesheet completely.

try https://treeherder.mozilla.org/#/jobs?repo=try&revision=0928f9775ec2b09a1dc7ba3e85e948c6ea3dd829

Comment on attachment 8827302 [details] Bug 1331510 - remove unused shared/widgets.css stylesheet from inspector.xhtml; https://reviewboard.mozilla.org/r/105014/#review105910

Pushed by jdescottes@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/9a55df40a9a8 remove unused shared/widgets.css stylesheet from inspector.xhtml;r=pbro

Please request Aurora approval on this when you get a chance.

Comment on attachment 8827302 [details] Bug 1331510 - remove unused shared/widgets.css stylesheet from inspector.xhtml; Approval Request Comment [Feature/Bug causing the regression]:1309733 [User impact if declined]: no direct user impact, but a devtools panel attempts to load a non-existing css which logs confusing errors for developers (cf Bug 1330123) [Is this code covered by automated tests?]: no [Has the fix been verified in Nightly?]: no [Needs manual test from QE? If yes, steps to reproduce]: no [List of other uplifts needed for the feature/fix]: none [Is the change risky?]: no [Why is the change risky/not risky?]: we just removed the link tag pointing to the non-existing css. This can't have any impact. [String changes made/needed]: none

Comment on attachment 8827302 [details] Bug 1331510 - remove unused shared/widgets.css stylesheet from inspector.xhtml; devtools inspector fix, aurora52+