Comment 0 for bug 1787460

On a fairly fresh install of 18.04 with no modifications whatsoever to the unattended-upgrades configuration, it decided to remove linux-image-generic which also removed linux-modules-extra which caused sound drivers to disappear, etc.

The relative snippet from /var/log/unattended-upgrades/unattended-upgrades.log is:

2018-08-15 06:18:00,048 INFO Starting unattended upgrades script
2018-08-15 06:18:00,048 INFO Allowed origins are: o=Ubuntu,a=bionic, o=Ubuntu,a=bionic-security, o=UbuntuESM,a=bionic
2018-08-15 06:18:01,552 INFO Removing unused kernel packages: linux-headers-generic linux-image-generic linux-headers-4.15.0-32-generic linux-headers-4.15.0-32
2018-08-15 06:18:01,588 WARNING Keeping auto-removable linux-headers-generic package(s) because it would also remove the following packages which should be kept in this step: libxml2 linux-image-4.15.0-32-generic linux-modules-4.15.0-32-generic linux-modules-extra-4.15.0-32-generic
2018-08-15 06:18:09,476 INFO Packages that were successfully auto-removed: linux-headers-4.15.0-32 linux-headers-4.15.0-32-generic linux-headers-generic linux-image-generic
2018-08-15 06:18:09,477 INFO Packages that are kept back: linux-headers-generic
2018-08-15 06:18:10,300 INFO Packages that will be upgraded: libxml2 linux-image-generic
2018-08-15 06:18:10,300 INFO Writing dpkg log to /var/log/unattended-upgrades/unattended-upgrades-dpkg.log
2018-08-15 06:18:39,238 INFO All upgrades installed
2018-08-15 06:18:42,818 INFO Packages that were successfully auto-removed: linux-image-generic linux-modules-extra-4.15.0-32-generic
2018-08-15 06:18:42,818 INFO Packages that are kept back:

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: unattended-upgrades 1.1ubuntu1.18.04.5
ProcVersionSignature: Ubuntu 4.15.0-32.35-generic 4.15.18
Uname: Linux 4.15.0-32-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.9-0ubuntu7.3
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Aug 16 13:17:30 2018
InstallationDate: Installed on 2018-07-24 (23 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180724)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unattended-upgrades
UpgradeStatus: No upgrade log present (probably fresh install)