Upgrade doesn't respect proprietary driver selection

[Kev Bowring]

Upgraded Bionic to Cosmic with iso from 13/10.

Prior to upgrading was using the nouveau driver.

Had previously installed nvidia to test a recent SRU fix. Once I had tested the fix I had gone back to additional drivers to revert to nouveau. Attached 2 screenshots from during the b-c upgrade and post upgrade - I've now got nvidia installed once more.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: software-properties-common 0.96.27
ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12
Uname: Linux 4.18.0-10-generic x86_64
ApportVersion: 2.20.10-0ubuntu13
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Oct 15 17:32:34 2018
InstallationDate: Installed on 2018-08-27 (49 days ago)
InstallationMedia: Xubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180824)
PackageArchitecture: all
SourcePackage: software-properties
UpgradeStatus: Upgraded to cosmic on 2018-10-14 (1 days ago)
modified.conffile..etc.default.apport: [modified]
mtime.conffile..etc.default.apport: 2018-09-21T16:30:23.845026

[Kev Bowring (flocculant)]

Attaching logs from /var/log/dist-upgrade

[Adam Conrad (adconrad)]

To be clear, nvidia was never removed, as far as I can tell, but it was installed and then nouveau selected as the default. So, the upgrade upgraded nvidia (which is fine), but then the default became nvidia again.

Not sure what should really happen in this case, or if maybe selecting nouveau should tear out all the nvidia bits.

[Kev Bowring (flocculant)]

@adconrad - ack. Just a comment - This time there was less than a month between installing this bionic instance, doing the sru test and then reverting - so I had at least some recollection of what went on. If it had been 3 years - I'd have no chance and would wonder what was going on. I guess I'd always assumed that reverting uninstalled - I knew it didn't remove the package(s) though.