Release Upgrader unable to determine upgrade 17.10 -> 18.04

[Laurie]

I tried running the upgrade, and it failed with this error. I saw the other bug https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1767436 that seemed to be a related issue, however I went back and manually disabled any third-party repos I had setup in the sources list and tried again, to no avail. I got the same exact error after disabling those repos.

I was also previously using the https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers but I used `ppa-purge` to remove this before attempting the upgrade, as I've heard that it can cause a broken machine if not removed first.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: ubuntu-release-upgrader-core 1:17.10.11
ProcVersionSignature: Ubuntu 4.13.0-46.51-generic 4.13.16
Uname: Linux 4.13.0-46-generic x86_64
NonfreeKernelModules: talpa_vfshook talpa_pedconnector talpa_pedevice talpa_vcdevice talpa_core talpa_linux talpa_syscallhook nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.7-0ubuntu3.9
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: KDE
Date: Fri Jul 20 17:20:23 2018
InstallationDate: Installed on 2017-11-08 (254 days ago)
InstallationMedia: Kubuntu 17.10 "Artful Aardvark" - Release amd64 (20171017.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to artful on 2018-07-20 (0 days ago)

[Laurie (ljl069)]

Do I need to remove any of my installed packages in order to get this upgrade to work correctly? If so, which ones do I need to remove, and will I be able to safely reinstall them after the upgrade? Also, what is the best way to get a list of packages/repos I currently have installed as a backup, so that I can more easily reinstall things once the upgrade's been completed successfully?

[Brian Murray (brian-murray)]

Reviewing the files from your upgrade attempt you seem to have enabled a PPA that provides Xorg packages. This will prevent the upgrade as that PPA contains package version numbers greater than the release to which you are upgrading. You can revert the PPA by installing the ppa-purge package from the official Ubuntu archive and then running 'sudo ppa-purge oibaf'. After that you try upgrading and again and if it still fails open a new bug report. Thanks and good luck!