package grub-efi-amd64-signed 1.93.22 2.02-2ubuntu8.20 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1

[Stefan Foulis]

I was told to report this by do-release-upgrade while upgrading from 16.04.

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: grub-efi-amd64-signed 1.93.22+2.02-2ubuntu8.20
ProcVersionSignature: Ubuntu 4.4.0-197.229-generic 4.4.241
Uname: Linux 4.4.0-197-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.21
Architecture: amd64
Date: Sun Dec 27 23:50:07 2020
ErrorMessage: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2017-10-11 (1173 days ago)
InstallationMedia: Ubuntu-Server 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
Python3Details: /usr/bin/python3.6, Python 3.6.9, python3-minimal, 3.6.7-1~18.04
PythonDetails: /usr/bin/python2.7, Python 2.7.17, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2.3
 apt 1.6.12ubuntu0.2
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.93.22+2.02-2ubuntu8.20 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to bionic on 2020-12-27 (0 days ago)