Public bug reported: Upgrade from 18.04. After this error the upgrade halted and the machine needed to be restarted with a live USB stick (as it would not boot into the semi-upgraded system), I then chrooted into the system and followed the instructions here https://ostechnix.com/how-to-fix-broken-ubuntu-os- without-reinstalling-it/ to be able to boot into 20.04
ProblemType: Package DistroRelease: Ubuntu 20.04 Package: grub-pc 2.04-1ubuntu26.4 ProcVersionSignature: Ubuntu 5.4.0-48.52-generic 5.4.60 Uname: Linux 5.4.0-48-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.9 Architecture: amd64 CasperMD5CheckResult: skip Date: Mon Oct 12 23:03:35 2020 DuplicateSignature: package:grub-pc:2.04-1ubuntu26.4 Setting up grub-pc (2.04-1ubuntu26.4) ... dpkg: error processing package grub-pc (--configure): installed grub-pc package post-installation script subprocess returned error exit status 1 ErrorMessage: installed grub-pc package post-installation script subprocess returned error exit status 1 InstallationDate: Installed on 2019-07-07 (463 days ago) InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210) ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-48-generic root=UUID=75277517-eb28-4f84-b3cb-8ab29620ed1c ro quiet splash vt.handoff=7 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 2.0.2ubuntu0.1 SourcePackage: grub2 Title: package grub-pc 2.04-1ubuntu26.4 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 1 UpgradeStatus: Upgraded to focal on 2020-10-12 (0 days ago) ** Affects: grub2 (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-package focal -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1899610 Title: package grub-pc 2.04-1ubuntu26.4 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1899610/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs