package libgcc1 1:8.4.0-1ubuntu1~18.04 failed to install/upgrade: package libgcc1:amd64 (1:10.2.0-5ubuntu1~20.04) with field 'Multi-Arch: no' is not co-installable with libgcc1 which has multiple installed instances

[Mike Varney]

Upgrading from bionic to focal.

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: libgcc1 1:8.4.0-1ubuntu1~18.04
ProcVersionSignature: Ubuntu 4.15.0-136.140-generic 4.15.18
Uname: Linux 4.15.0-136-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.23
Architecture: amd64
Date: Wed Mar 10 14:54:20 2021
DuplicateSignature:
 package:libgcc1:1:8.4.0-1ubuntu1~18.04
 Unpacking libqt5printsupport5:amd64 (5.12.8+dfsg-0ubuntu1) over (5.9.5+dfsg-0ubuntu2.5) ...
 dpkg: error processing archive /tmp/apt-dpkg-install-XtmfMN/93-libgcc1_1%3a10.2.0-5ubuntu1~20.04_amd64.deb (--unpack):
  package libgcc1:amd64 (1:10.2.0-5ubuntu1~20.04) with field 'Multi-Arch: no' is not co-installable with libgcc1 which has multiple installed instances
ErrorMessage: package libgcc1:amd64 (1:10.2.0-5ubuntu1~20.04) with field 'Multi-Arch: no' is not co-installable with libgcc1 which has multiple installed instances
InstallationDate: Installed on 2015-02-06 (2224 days ago)
InstallationMedia: Ubuntu-Server 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.3)
Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: /usr/bin/python2.7, Python 2.7.18, python-is-python2, 2.7.17-4
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.4
SourcePackage: gcc-8
Title: package libgcc1 1:8.4.0-1ubuntu1~18.04 failed to install/upgrade: package libgcc1:amd64 (1:10.2.0-5ubuntu1~20.04) with field 'Multi-Arch: no' is not co-installable with libgcc1 which has multiple installed instances
UpgradeStatus: Upgraded to focal on 2021-03-10 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.