dnsmasq cannot execute at systemctl

[Nick Sillito]

Using Ubuntu 24.04 I get a 'could not execute error:

sudo apt install dnsmasq
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed
  dnsmasq
0 to upgrade, 1 to newly install, 0 to remove and 14 not to upgrade.
Need to get 0 B/17.9 kB of archives.
After this operation, 88.1 kB of additional disk space will be used.
Selecting previously unselected package dnsmasq.
(Reading database ... 273753 files and directories currently installed.)
Preparing to unpack .../dnsmasq_2.90-2build2_all.deb ...
Unpacking dnsmasq (2.90-2build2) ...
Setting up dnsmasq (2.90-2build2) ...
Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 148.

apt-cache policy dnsmasq
dnsmasq:
  Installed: (none)
  Candidate: 2.90-2build2
  Version table:
     2.90-2build2 500
        500 http://gb.archive.ubuntu.com/ubuntu noble/universe amd64 Packages
        500 http://gb.archive.ubuntu.com/ubuntu noble/universe i386 Packages

[Lucas Kanashiro (lucaskanashiro)]

Thanks for taking the time to report this bug and trying to make Ubuntu better.

I tried to install dnsmasq in a brand new LXD container running Noble (24.04) and I was not able to reproduce the failure you mentioned:

root@dnsmasq-install:~# apt install dnsmasq
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  dns-root-data dnsmasq-base
The following NEW packages will be installed:
  dns-root-data dnsmasq dnsmasq-base
0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
Need to get 397 kB of archives.
After this operation, 953 kB of additional disk space will be used.
Do you want to continue? [Y/n]
Get:1 http://archive.ubuntu.com/ubuntu noble/main amd64 dnsmasq-base amd64 2.90-2build2 [375 kB]
Get:2 http://archive.ubuntu.com/ubuntu noble/universe amd64 dnsmasq all 2.90-2build2 [17.9 kB]
Get:3 http://archive.ubuntu.com/ubuntu noble/main amd64 dns-root-data all 2023112702~willsync1 [4450 B]
Fetched 397 kB in 3s (157 kB/s)
Selecting previously unselected package dnsmasq-base.
(Reading database ... 34374 files and directories currently installed.)
Preparing to unpack .../dnsmasq-base_2.90-2build2_amd64.deb ...
Unpacking dnsmasq-base (2.90-2build2) ...
Selecting previously unselected package dnsmasq.
Preparing to unpack .../dnsmasq_2.90-2build2_all.deb ...
Unpacking dnsmasq (2.90-2build2) ...
Selecting previously unselected package dns-root-data.
Preparing to unpack .../dns-root-data_2023112702~willsync1_all.deb ...
Unpacking dns-root-data (2023112702~willsync1) ...
Setting up dnsmasq-base (2.90-2build2) ...
Setting up dns-root-data (2023112702~willsync1) ...
Setting up dnsmasq (2.90-2build2) ...
Created symlink /etc/systemd/system/multi-user.target.wants/dnsmasq.service → /u
sr/lib/systemd/system/dnsmasq.service.
Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 148.
Processing triggers for man-db (2.12.0-4build2) ...
Processing triggers for dbus (1.14.10-4ubuntu4) ...
Scanning processes...

No services need to be restarted.

No containers need to be restarted.

No user sessions are running outdated binaries.

No VM guests are running outdated hypervisor (qemu) binaries on this host.
root@dnsmasq-install:~#

Not sure how to trigger the problem you described, and without that we cannot do anything. I am marking this bug as Incomplete as I cannot verify whether it is a real bug.

[Nick Sillito (nick-sillitos)]

Thanks for checking, just looking through your output, you have the same issue as me (just before the Processing.theiggers for man-db) you have the message 'Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 148.'

Having dug a bit further, this is because dnsmasq cannot listen on port 53 (resolv is already listening here). Disabling resolv solves the issue, so I think that the only issue here is that the error message isn't very clear (at lease to me)