package v4l2loopback-dkms 0.12.3-1 failed to install/upgrade: installed v4l2loopback-dkms package post-installation script subprocess returned error exit status 10

[Scott Saponas]

Failed to install on Surface Laptop 2

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: v4l2loopback-dkms 0.12.3-1
Uname: Linux 5.6.14-surface x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
Date: Mon May 25 11:38:33 2020
ErrorMessage: installed v4l2loopback-dkms package post-installation script subprocess returned error exit status 10
InstallationDate: Installed on 2020-05-23 (1 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
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: v4l2loopback
Title: package v4l2loopback-dkms 0.12.3-1 failed to install/upgrade: installed v4l2loopback-dkms package post-installation script subprocess returned error exit status 10
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[dan mackinlay (dan-possumpalace)]

The original bug does not include the make.log mentioned in the build error.
Here is a make log, which at least results in the same error code.

NB this is for a slightly different system, being DKMS make.log for v4l2loopback-0.12.3 for kernel 5.8.0-25-generic (x86_64)

[dan mackinlay (dan-possumpalace)]

Duplicate of #1883721 ?