Comment 10 for bug 2003201

After some discussion with the team it appears the only sensible option here is 2: update the representation of the test deb within the unshare test. The attached debdiff applies this and fixes a couple of other lintian errors (obsolete dependencies); I've tested this locally in a lunar VM successfully, and a test package is building in ppa:waveform/sbuild (https://launchpad.net/~waveform/+archive/ubuntu/sbuild) if anyone else wants a try.

I'll forward all these changes up to Debian, but if someone could have a look at sponsoring this in the meantime, I'd be most grateful.