NUT installation problem with 6.12.51+rpt-rpi-v8 on Trixie 32-bit (Lite and Desktop)

Reproduce the hang with apt-get install nut on Trixie 32-bit using kernels 6.12.47+rpt-rpi-v8 and 6.12.51+rpt-rpi-v8. Start by examining the reported /usr/bin/deb-systemd-invoke failure and comparing behavior across the listed kernel and system variants. Done means documenting the regression's cause and an appropriate fix or upstream handoff.

Describe the bug

NUT installation error on Trixie 32-bit using kernel 6.12.51+rpt-rpi-v8 on Trixie 32-bit (Lite and Desktop):

root@raspberrypi:~# apt-get -y update
Hit:1 http://archive.raspberrypi.com/debian trixie InRelease
Hit:2 http://raspbian.raspberrypi.com/raspbian trixie InRelease
All packages are up to date.

root@raspberrypi:~# apt-get -y install nut
Reading package lists... Done
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
libnutscan2 libupsclient6t64 nut-client nut-server
Suggested packages:
nut-monitor nut-cgi nut-i2c nut-ipmi nut-modbus nut-snmp nut-xml
The following NEW packages will be installed:
libnutscan2 libupsclient6t64 nut nut-client nut-server
0 upgraded, 5 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/3,226 kB of archives.
After this operation, 12.2 MB of additional disk space will be used.
Selecting previously unselected package libupsclient6t64:armhf.
(Reading database ... 120587 files and directories currently installed.)
Preparing to unpack .../libupsclient6t64_2.8.1-5_armhf.deb ...
Adding 'diversion of /lib/arm-linux-gnueabihf/libupsclient.so.6 to /lib/arm-linux-gnueabihf/libupsclient.so.6.usr-is-merged by libupsclient6t64'
Adding 'diversion of /lib/arm-linux-gnueabihf/libupsclient.so.6.0.1 to /lib/arm-linux-gnueabihf/libupsclient.so.6.0.1.usr-is-merged by libupsclient6t64'
Unpacking libupsclient6t64:armhf (2.8.1-5) ...
Selecting previously unselected package nut-client.
Preparing to unpack .../nut-client_2.8.1-5_armhf.deb ...
Unpacking nut-client (2.8.1-5) ...
Selecting previously unselected package libnutscan2:armhf.
Preparing to unpack .../libnutscan2_2.8.1-5_armhf.deb ...
Unpacking libnutscan2:armhf (2.8.1-5) ...
Selecting previously unselected package nut-server.
Preparing to unpack .../nut-server_2.8.1-5_armhf.deb ...
Unpacking nut-server (2.8.1-5) ...
Selecting previously unselected package nut.
Preparing to unpack .../archives/nut_2.8.1-5_all.deb ...
Unpacking nut (2.8.1-5) ...
Setting up libupsclient6t64:armhf (2.8.1-5) ...
Removing 'diversion of /lib/arm-linux-gnueabihf/libupsclient.so.6 to /lib/arm-linux-gnueabihf/libupsclient.so.6.usr-is-merged by libupsclient6t64'
Removing 'diversion of /lib/arm-linux-gnueabihf/libupsclient.so.6.0.1 to /lib/arm-linux-gnueabihf/libupsclient.so.6.0.1.usr-is-merged by libupsclient6t64'
Setting up nut-client (2.8.1-5) ...
Created symlink '/etc/systemd/system/upsmon.service' ā†’ '/usr/lib/systemd/system/nut-monitor.service'.
Created symlink '/etc/systemd/system/nut.target.wants/nut-monitor.service' ā†’ '/usr/lib/systemd/system/nut-monitor.service'.
Created symlink '/etc/systemd/system/multi-user.target.wants/nut.target' ā†’ '/usr/lib/systemd/system/nut.target'.
Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 148.
Setting up libnutscan2:armhf (2.8.1-5) ...
Setting up nut-server (2.8.1-5) ...
/usr/lib/tmpfiles.d/nut-server.conf:1: Duplicate line for path "/run/nut", ignoring.
Created symlink '/etc/systemd/system/nut.target.wants/nut-driver-enumerator.path' ā†’ '/usr/lib/systemd/system/nut-driver-enumerator.path'.
Created symlink '/etc/systemd/system/nut.target.wants/nut-driver-enumerator.service' ā†’ '/usr/lib/systemd/system/nut-driver-enumerator.service'.
Created symlink '/etc/systemd/system/nut.target.wants/nut-driver.target' ā†’ '/usr/lib/systemd/system/nut-driver.target'.
Created symlink '/etc/systemd/system/upsd.service' ā†’ '/usr/lib/systemd/system/nut-server.service'.
Created symlink '/etc/systemd/system/nut.target.wants/nut-server.service' ā†’ '/usr/lib/systemd/system/nut-server.service'.

***** Installation hangs for a long time here before reporting:

Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 148.

Setting up nut (2.8.1-5) ...
Processing triggers for man-db (2.13.1-1) ...
Processing triggers for libc-bin (2.41-12+rpt1) ...

Steps to reproduce the behaviour

1. Replace kernel 6.12.47+rpt-rpi-v8 with 6.12.51+rpt-rpi-v8 on Trixie 32-bit

2. Install NUT

Device (s)

Raspberry Pi 5

System

root@raspberrypi:~# cat /etc/rpi-issue
Raspberry Pi reference 2025-10-01
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 7385adde4cd7a2bfcf6e6ef0e5b790391c172a8d, stage2

root@raspberrypi:~# vcgencmd version
2025/08/27 20:01:47
Copyright (c) 2012 Broadcom
version 000d3ca2 (release) (embedded)

root@raspberrypi:~# uname -a
Linux raspberrypi 6.12.51+rpt-rpi-v8 #1 SMP PREEMPT_RT Mon Oct 6 12:45:18 CDT 2025 aarch64 GNU/Linux

Logs

No response

Additional context

Problem does not occur with kernel 6.12.47+rpt-rpi-v8 on Trixie 32-bit

Problem does not occur with kernel 6.12.51+rpt-rpi-2712 on Trixie 64-bit