20.04 update registering bad ppas

[Lawrence Hammond]

Updating to 20.04 from 18.04 complains about ppas. I think it's the wine ppa for Bionic not having a release file, but I have disabled as far as apt update and apt upgrade go so I don't know how to proceed. /var/log/dist-upgrade/main.log mentions broken packages after upgrading ubuntu-desktop, but I don't know quite enough about how to read main.log and apt.log to provide more useful information than that.

Essentially, I expected an upgrade and got an error message about "an unsolvable problem... likely caused by unofficial software packages." It suggested purging ppas with ppa-purge, which I have already done.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-release-upgrader-core 1:18.04.40
ProcVersionSignature: Ubuntu 4.15.0-124.127-generic 4.15.18
Uname: Linux 4.15.0-124-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.20
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Mon Nov 30 10:03:34 2020
InstallationDate: Installed on 2020-10-17 (44 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
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 2020-11-30 (0 days ago)