Comment 105 for bug 2059847

> First time I've experienced broken --> fixed --> broken (in exact manner
> as pre-fix) of a STANDARD package from OFFICIAL sources.

That is not an accurate description of the events here. This was an issue
introduced in mutter 45.2-0ubuntu4 and 42.9-0ubuntu7. The only subsequent
versions of this package in official sources are 42.9-0ubuntu7.1 (which was
just published by the security team), and 45.2-0ubuntu5 nd 42.9-0ubuntu8
which are the fixes that have just been accepted into the -proposed pocket.

A fix in a test ppa is not an "official" source.