The stylesheet actor can request an original source by trying to fetch its URL, even when the source is available in the source map itself. See https://github.com/mozilla/source-map/issues/211 for details. It links to a reproducer: https://github.com/glen-84/ff-sourcemaps-issue This will necessarily be fixed once bug 1179820 is done. However it would be nice to verify the fix, perhaps by landing a test case here.

I think the basic issue is that the stylesheet actor passes in the full URL; but the source map library won't accept this when the sourceRoot is relative. https://github.com/mozilla/source-map/pull/282 should fix that.

I think I'll land a new source-map bundle here in the interim. This will fix the problem and hedge against not converting the inspector.

Actually, I'll just file a new bug for landing the bundle. At some point we may still want a test here.

There's a test upstream and the inspector is using client-side source maps now, so closing.