Comment 2 for bug 2039752

Relevant Dpkg errors:

openssh-server (1:9.0p1-1ubuntu8.5) over (1:9.0p1-1ubuntu8)
...
Setting up openssh-server (1:9.0p1-1ubuntu8.5) ...
rescue-ssh.target is a disabled or a static unit not running, not starting it.
Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 145.
dpkg: error processing package openssh-server (--configure):
 installed openssh-server package post-installation script subprocess returned error exit status 1

So this error was seen when upgrading from the release version of openssh in Lunar to the current latest version in updates.

I tried to reproduce in an lxc container. Had to downgrade 2 packages like so:
$ lxc launch ubuntu:lunar l
$ lxc shell l
# apt install -y openssh-client=1:9.0p1-1ubuntu8 -y --allow-downgrades
# apt install -y openssh-sftp-server=1:9.0p1-1ubuntu8 -y --allow-downgrades

upon downgrading openssh-server I see this error

Selecting previously unselected package openssh-server.
(Reading database ... 33940 files and directories currently installed.)
Preparing to unpack .../openssh-server_1%3a9.0p1-1ubuntu8_amd64.deb ...
Unpacking openssh-server (1:9.0p1-1ubuntu8) ...
Setting up openssh-server (1:9.0p1-1ubuntu8) ...
rescue-ssh.target is a disabled or a static unit not running, not starting it.
Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 145.
dpkg: error processing package openssh-server (--configure):
 installed openssh-server package post-installation script subprocess returned error exit stat
us 1
dmesg: read kernel buffer failed: Operation not permitted
                                                         Processing triggers for man-db (2.11.
2-1) ...
Processing triggers for ufw (0.36.1-4.1ubuntu0.1) ...
Errors were encountered while processing:
 openssh-server
needrestart is being skipped since dpkg has failed
E: Sub-process /usr/bin/dpkg returned an error code (1)

Attempting to upgrade to 8.5 I see:

root@l:~# apt-cache policy openssh-server
Setting up openssh-client (1:9.0p1-1ubuntu8.5) ...
Setting up openssh-sftp-server (1:9.0p1-1ubuntu8.5) ...
Setting up openssh-server (1:9.0p1-1ubuntu8.5) ...
rescue-ssh.target is a disabled or a static unit not running, not starting it.
Could not execute systemctl: at /usr/bin/deb-systemd-invoke line 145.
dpkg: error processing package openssh-server (--configure):
 installed openssh-server package post-installation script subprocess returned error exit stat
us 1
dmesg: read kernel buffer failed: Operation not permitted
                                                         Processing triggers for man-db (2.11.
2-1) ...
Processing triggers for ufw (0.36.1-4.1ubuntu0.1) ...
Errors were encountered while processing:
 openssh-server
needrestart is being skipped since dpkg has failed
E: Sub-process /usr/bin/dpkg returned an error code (1)