lubuntu-desktop is preventing upgrade to 20.04

[Christian Smith]

update-manager -d run from the shell.

Upgrading from 19.10, upgrade fails with this error in main.log:

2020-04-13 16:52:58,939 WARNING Can't mark 'lubuntu-desktop' for upgrade (E:Unable to correct problems, you have held broken packages.)
2020-04-13 16:56:26,907 ERROR Dist-upgrade failed: 'Broken packages after upgrade: lubuntu-desktop'

I would expect that lubuntu-desktop would be in a state that would allow upgrade to succeed.

I will retry with lubuntu-desktop removed.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: ubuntu-release-upgrader-core 1:19.10.15.4
ProcVersionSignature: Ubuntu 5.3.0-46.38-generic 5.3.18
Uname: Linux 5.3.0-46-generic x86_64
ApportVersion: 2.20.11-0ubuntu8.8
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: LXQt
Date: Tue Apr 14 02:04:54 2020
InstallationDate: Installed on 2017-11-27 (868 days ago)
InstallationMedia: Lubuntu 17.10 "Artful Aardvark" - Release amd64 (20171017.1)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to eoan on 2020-04-13 (0 days ago)
VarLogDistupgradeTermlog:

[Chris Guiver (guiverc)]

Thank you for taking the time to report this issue and helping to make Ubuntu better.

It looks to me that Unofficial software packages (not provided by Ubuntu) have been added to your system, ie. one problem is

Broken libuno-sal3:amd64 Breaks on uno-libs3:amd64 < 6.3.5-0ubuntu0.19.10.1

I found no Ubuntu package of that name, and the package appears to be https://packages.debian.org/bullseye/libuno-sal3

I've marked this incomplete, as this issue appears to be created by 3rd party packages. If you believe I'm in error, you can return status to 'New' after leaving a message explaining why, or what I've missed.

[Brian Murray (brian-murray)]

This is actually because you have removed the xscreensaver package from your system. Please reinstall it and try the upgrade again. From VarLogDistUpgradeAptterm.log:

  Installing xscreensaver as Depends of lubuntu-desktop
    Ignore MarkInstall of xscreensaver:amd64 < 5.42+dfsg1-1ubuntu1 @ii pgR NPb > as its mode (Delete) is protected