users plugin broken with systemd changes

[dgilman]

Describe the bug
On the latest debian (trixie) the users plugin does not correctly identify pts users because the format of the utmp device name line changed.

For some background, see https://bugzilla.redhat.com/show_bug.cgi?id=2343998 and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1112071 . The root cause seems to be:

• systemd creates utmp entries with a space in them (sshd pts/0) which throws off the regex in the munin plugin
• who does not have a well-structured, parseable output format (there isn't a \t delimiter or something like that)
• debian, and possibly other systems, no longer ship a utmpdump program. That program is meant to give a well-structured, parseable output which would be an ideal replacement for who.
• debian, and possibly other systems, now use wtmpdb as a backend for the wtmp file. However, doing a strace on who reveals that who/systemd is not opening the wtmpdb sqlite3 database to discover entries but instead browsing /run/systemd/sessions/.

I am not sure what the most reliable fix is here. The regex could be tweaked a bit. However, maybe it is worth moving to wtmpdb, loginctl, or utmpdump?

To Reproduce
Run users plugin on a Debian 13 system.

Expected behavior
A SSH login is parsed as a pts login, not as an other type.

Screenshots & Logs

root@dgilman:/etc/munin/plugins# ./users
tty.value 0
pty.value 0
pts.value 0
X.value 0
other.value 1

root@dgilman:/etc/munin/plugins# ls -alh users
lrwxrwxrwx 1 root root 30 Feb 26  2014 users -> /usr/share/munin/plugins/users

root@dgilman:/etc/munin/plugins# who
david    sshd pts/0   2025-08-25 16:19 (666.777.888.999)

Desktop (please complete the following information):
Debian 13

Additional context
n/a