package grub-pc 2.04-1ubuntu12.1 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 1

[Jonastar]

automatic update from Ubuntu 19.10 file system zol

ProblemType: Package
DistroRelease: Ubuntu 19.10
Package: grub-pc 2.04-1ubuntu12.1
ProcVersionSignature: Ubuntu 5.3.0-23.25-generic 5.3.7
Uname: Linux 5.3.0-23-generic x86_64
NonfreeKernelModules: nvidia zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu8.4
Architecture: amd64
Date: Sat Feb 22 17:37:13 2020
ErrorMessage: installed grub-pc package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2019-11-16 (97 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
ProcCmdLine: BOOT_IMAGE=/BOOT/ubuntu_tlqbjg@/vmlinuz-5.3.0-23-generic root=ZFS=rpool/ROOT/ubuntu_tlqbjg ro quiet splash vt.handoff=1
Python3Details: /usr/bin/python3.7, Python 3.7.5, python3-minimal, 3.7.5-1
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu2
 apt 1.9.4
SourcePackage: grub2
Title: package grub-pc 2.04-1ubuntu12.1 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Anthony Borrow (arborrow)]

Any thoughts on a workaround or next best steps? Anything dealing with grub always scares me because it impacts rebooting.

[Anthony Borrow (arborrow)]

I have two instances running with the same provider (Linode). One upgraded fine about a month ago. The other has this grub-pc error. The only differences I noted in the /boot/grub folder was that the one that is not working has the default and menu.lst files present. Not sure if it is related but it would appear (anecdotally) that something changed between my upgrading of the two instances.