Comment 12 for bug 1460152

@all I just verified that a 15.04/stable -> 15.04/edge upgrade works and that the caches are regenerated. So the workaround works.

@John I started with the mtime approach in my proof of concept patch. So if you guys are too busy I can try to expand it to cover the includes as well (it does not right now). Great to hear that we are close to nice and clean solution :)

@Jamie Thanks for your feedback! I haven't considered the #includes, thats a gap in the patch indeed.