Code review comment for lp://staging/~benji/landscape-client/bug-1548946-xenial-test-failures

> I'm basically +1 with a non-blocking nitpick.
>
> Just marking as Needs information because of the following question.
>
> Since it seems you investigated the issue in depth and possible looked at the
> changed behavior in the apt module, do you think it would be possible to avoid
> using the TestCache and change the test to adapt to the new behavior somehow?
> Or is it now plain impossible for calling code to have visibility on that?

I spent a (timeboxed) bit of time trying to discern exactly how the cache's behaviour has changed, and I couldn't figure enough out to exploit it for our tests.

Arguably, exploiting said details is what got us into this situation, but I wouldn't argue that too strenuously.