package grub-pc 2.04-1ubuntu26.7 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 1

[Muhammad Taha Farooq]

I am new user of Ubuntu I dont know much about the bugs and their details

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: grub-pc 2.04-1ubuntu26.7
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
CasperMD5CheckResult: skip
Date: Fri Dec 18 20:11:16 2020
DuplicateSignature:
 package:grub-pc:2.04-1ubuntu26.7
 Setting up memtest86+ (5.01-3.1ubuntu2.1) ...
 /usr/sbin/grub-probe: error: failed to get canonical path of `rpool/ROOT/ubuntu_pnlrk9'.
 dpkg: error processing package memtest86+ (--configure):
  installed memtest86+ 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 2020-12-17 (0 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
ProcCmdLine: BOOT_IMAGE=/BOOT/ubuntu_pnlrk9@/vmlinuz-5.4.0-42-generic root=ZFS=rpool/ROOT/ubuntu_pnlrk9 ro quiet splash vt.handoff=1
Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.2ubuntu0.2
SourcePackage: grub2
Title: package grub-pc 2.04-1ubuntu26.7 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.