package grub-pc 2.04-1ubuntu26.12 failed to install/upgrade: installed grub-pc package post-installation script subprocess returned error exit status 127

[Mike Rudd]

Don't know enough to provide more info.

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: grub-pc 2.04-1ubuntu26.12
ProcVersionSignature: Ubuntu 5.8.0-50.56~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-50-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.18
Architecture: amd64
CasperMD5CheckResult: skip
Date: Fri Jun 4 18:33:07 2021
DuplicateSignature:
 package:grub-pc:2.04-1ubuntu26.12
 Setting up grub-pc (2.04-1ubuntu26.12) ...
 /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 2021-05-08 (27 days ago)
InstallationMedia: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
InvalidGrubScript: /etc/default/grub
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.8.0-50-generic root=UUID=891fe260-86c8-4362-b5d4-2768480b646a ro quiet splash
Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.5
SourcePackage: grub2
Title: package grub-pc 2.04-1ubuntu26.12 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)

[Launchpad Janitor (janitor)]

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

[Mate Kukri (mkukri)]

This looks like a corrupted /etc/default/grub