package systemd-resolved 255.4-1ubuntu8 failed to install/upgrade: installed systemd-resolved package post-installation script subprocess returned error exit status 1 [cp: '/etc/resolv.conf' and '/run/systemd/resolve/stub-resolv.conf' are the same file]

[Michael Cain]

Trying to update 22.04.4 to 24.04

ProblemType: Package
DistroRelease: Ubuntu 24.04
Package: systemd-resolved 255.4-1ubuntu8
ProcVersionSignature: Ubuntu 6.5.0-28.29~22.04.1-generic 6.5.13
Uname: Linux 6.5.0-28-generic x86_64
ApportVersion: 2.28.1-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: pass
CloudArchitecture: x86_64
CloudID: none
CloudName: none
CloudPlatform: none
CloudSubPlatform: config
Date: Thu Apr 25 23:05:36 2024
ErrorMessage: installed systemd-resolved package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2024-04-09 (16 days ago)
InstallationMedia: Ubuntu-Server 22.04.4 LTS "Jammy Jellyfish" - Release amd64 (20240216.1)
Python3Details: /usr/bin/python3.12, Python 3.12.3, python3-minimal, 3.12.3-0ubuntu1
PythonDetails: N/A
RebootRequiredPkgs: Error: path contained symlinks.
RelatedPackageVersions:
 dpkg 1.22.6ubuntu6
 apt 2.7.14build2
SourcePackage: systemd
Title: package systemd-resolved 255.4-1ubuntu8 failed to install/upgrade: installed systemd-resolved package post-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to noble on 2024-04-26 (0 days ago)
mtime.conffile..etc.init.d.apport: 2024-04-18T19:50:32

[Michael Cain (cainmp)]

For context, on the 2 boxes I have that this effected, I have disabled the systemd stub resolver in order to allow AdGuard dns server listen on all interfaces. I am assuming that is the source of the problem.

[Nick Rosbrook (enr0n)]

How exactly did you disable the stub resolver?

[Nick Rosbrook (enr0n)]

And, if you still have an affected system in this state, what does readlink /etc/resolv.conf show?

[Michael Cain (cainmp)]

Per here: https://www.turek.dev/posts/disable-systemd-resolved-cleanly/ and the "Clean" solution

[Michael Cain (cainmp)]

cainmp@svr-ns1:~$ readlink /etc/resolv.conf
/run/systemd/resolve/resolv.conf

[Nick Rosbrook (enr0n)]

Ah, I see. Thanks for that link. The issue is that it is not actually necessary to make the /etc/resolv.conf -> /run/systemd/resolve/resolv.conf symlink. systemd-resolved will handle DNSStubListener=no by making /run/systemd/resolve/stub-resolv.conf a symlink to /run/systemd/resolve/resolv.conf.

Anyways, this gives me the info I need to write a patch. Thanks again.