Linux 5.15 for Ubuntu 20.04.5 cannot build nvidia-340 and let the default boot option unbootable

[Thomas Debesse]

Context: the computer is running nvidia-340 to workaround suspend bug happening when using nouveau.

Since more than a year, the system isn't bootable with the default boot option because nvidia-340 can't be built against newer default kernels.

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: nvidia-340 340.108-0ubuntu5.20.04.2
ProcVersionSignature: Ubuntu 5.8.0-63.71~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-63-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.20.11-0ubuntu27.24
Architecture: amd64
CasperMD5CheckResult: skip
DKMSKernelVersion: 5.15.0-46-generic
Date: Fri Sep 16 15:36:14 2022
InstallationDate: Installed on 2021-07-02 (440 days ago)
InstallationMedia: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
PackageVersion: 340.108-0ubuntu5.20.04.2
Python3Details: /usr/bin/python3.8, Python 3.8.10, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3.2
 apt 2.0.9
SourcePackage: nvidia-graphics-drivers-340
Title: nvidia-340 340.108-0ubuntu5.20.04.2: nvidia-340 kernel module failed to build
UpgradeStatus: No upgrade log present (probably fresh install)