"can't install kubuntu-desktop" on Kubuntu 18.04 upgrade from 16.04

[Angelos Pikoulas]

Once more I tried to upgrade latest Kubuntu 16.04.05 to 18.04 from the upgrade tool, I ended up with "Can't install 'kubutnu-desktop'".

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.25
ProcVersionSignature: Ubuntu 4.4.0-135.161-generic 4.4.140
Uname: Linux 4.4.0-135-generic x86_64
NonfreeKernelModules: wl nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: KDE
Date: Wed Sep 19 21:38:29 2018
InstallationDate: Installed on 2016-04-04 (897 days ago)
InstallationMedia: Kubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160323)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to xenial on 2018-09-19 (0 days ago)
VarLogDistupgradeTermlog:

[Brian Murray (brian-murray)]

From VarLogDistupgradeMainlog.txt:

2018-09-19 20:05:55,028 DEBUG none of the '['ubuntu-desktop', 'kubuntu-desktop', 'xubuntu-core', 'xubuntu-desktop', 'ubuntustudio-desktop', 'mythbuntu-desktop', 'kubuntu-netbook', 'lubuntu-core', 'lubuntu-desktop', 'ubuntu-gnome-desktop', 'ubuntu-mate-core', 'ubuntu-mate-cloudtop', 'ubuntu-mate-desktop', 'ubuntukylin-desktop']' meta-pkgs installed
2018-09-19 20:05:55,029 DEBUG guessing 'kubuntu-desktop' as missing meta-pkg
2018-09-19 20:05:55,299 ERROR failed to mark 'kubuntu-desktop' for install (E:Unable to correct problems, you have held broken packages.)

Please try installing kubuntu-desktop and then upgrading the system.

[Angelos Pikoulas (agelos-pikoulas)]

I installed `kubuntu-desktop` before the upgrade, ended up again in broken install.
I tried installing `kubuntu-desktop` again along with `apt --fix-broken-install`, and both seemed to have succeed but the system was again unusable.

[Launchpad Janitor (janitor)]

[Expired for ubuntu-release-upgrader (Ubuntu) because there has been no activity for 60 days.]