Code review comment for lp:~alan-griffiths/mir/fix-1543049

> Although it's clearly possible to set up a machine to make the test case in
> question fail, most peoples' machines are not failing any tests even while the
> bug exists.

All you need is a working copy in which you've built Mir. Then, as indicated in the bug, bump MIR_SERVER_GRAPHICS_PLATFORM_ABI and rebuild without cleaning lib/server-modules/.

This can happen in normal workflow either when you, or a branch you merge updates the graphics platform ABI. As noted in the bug deleting the old lib works around the problem.

AFAIK we've never yet replicated this problem with a release, but as Chris indicates, it could also impact some upgrade scenarios.

> So can we add a new unit test for the issue to cover that gap?

Hmm. Because the logic is hard coded to the real filesystem there's no convenient "seam" for testing, but I'll have a think about the best way to address this.