upgrade to latest stable release fails

[Don Harter]

Description: Ubuntu 18.04.5 LTS
Release: 18.04

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.40
ProcVersionSignature: Ubuntu 5.4.0-52.57~18.04.1-generic 5.4.65
Uname: Linux 5.4.0-52-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.18
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: LXDE
Date: Wed Oct 21 18:11:12 2020
InstallationDate: Installed on 2020-03-17 (217 days ago)
InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to bionic on 2020-10-21 (0 days ago)
VarLogDistupgradeTermlog:

[Don Harter (harterc2)]

This should be closed. I found out that I had packages from a ppa repository which were duplicates of standard ubuntu packages. So this bug report should not even been submited.

Useful commands to solve this problem were:
for name in `dpkg -l | gawk -e '{print $2}'` ; do apt-cache policy $name; done | grep ppa
ppa-purge ppa:ubuntugis