package initramfs-tools 0.137ubuntu12 failed to install/upgrade: installed initramfs-tools package post-installation script subprocess returned error exit status 1

new bug report because the other ones are 5+ years old

Ubuntu 20.10 on Raspberry Pi installed via PINN

ProblemType: Package
DistroRelease: Ubuntu 20.10
Package: initramfs-tools 0.137ubuntu12
ProcVersionSignature: Ubuntu 5.8.0-1006.9-raspi 5.8.14
Uname: Linux 5.8.0-1006-raspi aarch64
ApportVersion: 2.20.11-0ubuntu50.1
Architecture: arm64
CasperMD5CheckResult: skip
Date: Tue Nov 24 09:19:05 2020
ErrorMessage: installed initramfs-tools package post-installation script subprocess returned error exit status 1
ImageMediaBuild: 20201022
PackageArchitecture: all
Python3Details: /usr/bin/python3.8, Python 3.8.6, python3-minimal, 3.8.6-0ubuntu1
PythonDetails: N/A
RebootRequiredPkgs:
 gnome-shell
 linux-image-5.8.0-1007-raspi
 linux-base
RelatedPackageVersions:
 dpkg 1.20.5ubuntu2
 apt 2.1.10
SourcePackage: initramfs-tools
Title: package initramfs-tools 0.137ubuntu12 failed to install/upgrade: installed initramfs-tools package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)