Comment 9 for bug 1905377

Hi Paride,
This is tied into upgrade mechanisms (as that is what it needs to fix, long running qemu's through an upgrade)
It needs an upgrade to happen to enter the bad state:
That upgrade doesn't have to be another version

For example:
$ apt install qemu-block-extra
$ apt install --reinstall qemu-block-extra

Triggers the bug in a fresh container.

That very same test now works fine with the fix in https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/4348

The maintainer scrips look less normal/formal (no more based ont he usual skeleton), but they work - use the .debhelper suffix that seems to be established and align with how Debian does it.

Fix can be uploaded, I'm just waiting for a few other bugs we have open to decide if I do one or many uploads (test and build queue is full enough).