package grub-efi-amd64-signed 1.142.6+2.04-1ubuntu26.4 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1

[Ashwin]

The package isn't being updated

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: grub-efi-amd64-signed 1.142.6+2.04-1ubuntu26.4
ProcVersionSignature: Ubuntu 5.4.0-47.51-generic 5.4.55
Uname: Linux 5.4.0-47-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.8
Architecture: amd64
CasperMD5CheckResult: skip
Date: Sun Sep 20 10:01:45 2020
ErrorMessage: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2020-08-13 (37 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
Python3Details: /usr/bin/python3.8, Python 3.8.2, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.2ubuntu0.1
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.142.6+2.04-1ubuntu26.4 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)

[Launchpad Janitor (janitor)]

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

[Francis M (fmcbra)]

Hitting this bug and unsure now if we can safel reboot the affected box.

  (#) root@wither:~
  >>> dpkg --configure -a
  Setting up grub-efi-amd64-signed (1.142.6+2.04-1ubuntu26.4) ...
  dpkg: error processing package grub-efi-amd64-signed (--configure):
   installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
  Errors were encountered while processing:
   grub-efi-amd64-signed

Unsure if this is actually accurate but I've seen reference to this latest grub2-signed bug relating to an incorrectly configured ESP partition.

Note: this this hapening on a machine with non-GPT partition tables:

  Disk /dev/nvme0n1: 476.96 GiB, 512110190592 bytes, 1000215216 sectors
  Disk model: KXG50ZNV512G TOSHIBA
  Units: sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disklabel type: dos
  Disk identifier: 0xc3f69e73

  Device Boot Start End Sectors Size Id Type
  /dev/nvme0n1p1 2048 2099199 2097152 1G fd Linux raid autodetect
  /dev/nvme0n1p2 2099200 10487807 8388608 4G fd Linux raid autodetect
  /dev/nvme0n1p3 10487808 77596671 67108864 32G fd Linux raid autodetect
  /dev/nvme0n1p4 77596672 1000215215 922618544 440G 5 Extended
  /dev/nvme0n1p5 77598720 874516479 796917760 380G 83 Linux
  /dev/nvme0n1p6 874518528 1000215215 125696688 60G 83 Linux

Open to guinea-pigging fixes if any are uploaded and/or providing more information.