package grub-pc 2.02-2ubuntu8.12 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 127

[vishvajeet]

bug

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: grub-pc 2.02-2ubuntu8.12
ProcVersionSignature: Ubuntu 4.15.0-43.46-generic 4.15.18
Uname: Linux 4.15.0-43-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
Date: Wed Apr 3 12:56:28 2019
DuplicateSignature:
 package:grub-pc:2.02-2ubuntu8.12
 Setting up grub-pc (2.02-2ubuntu8.12) ...
 /var/lib/dpkg/info/grub-pc.config: 1: /etc/default/grub: If: not found
 dpkg: error processing package grub-pc (--configure):
  installed grub-pc package post-installation script subprocess returned error exit status 127
ErrorMessage: installed grub-pc package post-installation script subprocess returned error exit status 127
InstallationDate: Installed on 2019-01-07 (86 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
InvalidGrubScript: /etc/default/grub
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-43-generic root=UUID=28fe1d2f-c983-4bf9-9324-ec3c76ec690b ro quiet splash vt.handoff=1
Python3Details: /usr/bin/python3.6, Python 3.6.7, python3-minimal, 3.6.7-1~18.04
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2.1
 apt 1.6.10
SourcePackage: grub2
Title: package grub-pc 2.02-2ubuntu8.12 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 127
UpgradeStatus: No upgrade log present (probably fresh install)