package grub-efi-amd64-signed 1.108+2.02+dfsg1-5ubuntu6 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1

system was executing a system update and failed to do so.

ProblemType: Package
DistroRelease: Ubuntu 18.10
Package: grub-efi-amd64-signed 1.108+2.02+dfsg1-5ubuntu6
ProcVersionSignature: Ubuntu 4.18.0-9.10-generic 4.18.12
Uname: Linux 4.18.0-9-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.10-0ubuntu11
Architecture: amd64
Date: Mon Oct 8 16:27:21 2018
ErrorMessage: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
Python3Details: /usr/bin/python3.6, Python 3.6.7rc1, python3-minimal, 3.6.6-1
PythonDetails: /usr/bin/python2.7, Python 2.7.15+, python-minimal, 2.7.15-3
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu5
 apt 1.7.0
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.108+2.02+dfsg1-5ubuntu6 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)