package grub-pc 2.04-1ubuntu26.1 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 2

[Michel]

unable to upgrade

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: grub-pc 2.04-1ubuntu26.1
ProcVersionSignature: Ubuntu 5.4.0-37.41-generic 5.4.41
Uname: Linux 5.4.0-37-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: skip
Date: Thu Jul 30 09:13:25 2020
DpkgHistoryLog:
 Start-Date: 2020-07-30 09:12:59
 Requested-By: goltuna (1000)
 Upgrade: linux-headers-generic:amd64 (5.4.0.42.45, 5.4.0.42.46), grub-common:amd64 (2.04-1ubuntu26, 2.04-1ubuntu26.1), linux-image-generic:amd64 (5.4.0.42.45, 5.4.0.42.46), grub2-common:amd64 (2.04-1ubuntu26, 2.04-1ubuntu26.1), grub-pc:amd64 (2.04-1ubuntu26, 2.04-1ubuntu26.1), grub-pc-bin:amd64 (2.04-1ubuntu26, 2.04-1ubuntu26.1), linux-generic:amd64 (5.4.0.42.45, 5.4.0.42.46)
ErrorMessage: installed grub-pc package post-installation script subprocess returned error exit status 2
InstallationDate: Installed on 2020-04-07 (113 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Beta amd64 (20200402)
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-37-generic root=UUID=da9d24ca-41a3-4cfc-b078-6795f32d6994 ro quiet splash
Python3Details: /usr/bin/python3.8, Python 3.8.2, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.2ubuntu0.1
SourcePackage: grub2
Title: package grub-pc 2.04-1ubuntu26.1 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 2
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Steve Langasek (vorlon)]

What is /etc/grub.d/bin/grubcfg_proxy? This is not part of Ubuntu, and the error reported is related to this file. This doesn't look like a bug in Ubuntu's grub package.

[Launchpad Janitor (janitor)]

[Expired for grub2 (Ubuntu) because there has been no activity for 60 days.]