Failed to start user manager

1

This happens from time to time for a few users, and I have no idea how to debug it, as the error message is quite unspecific:

$ sudo systemctl status user@1008
● [email protected] - User Manager for UID 1008
     Loaded: loaded (/lib/systemd/system/[email protected]; static)
     Active: failed (Result: exit-code) since Fri 2023-11-24 14:40:24 CET; 3min 7s ago
       Docs: man:[email protected](5)
    Process: 302939 ExecStart=/lib/systemd/systemd --user (code=exited, status=1/FAILURE)
   Main PID: 302939 (code=exited, status=1/FAILURE)
        CPU: 15ms

Nov 24 14:40:23 main.iridion.it systemd[1]: Starting User Manager for UID 1008...
Nov 24 14:40:23 main.iridion.it systemd[302939]: pam_unix(systemd-user:session): session opened for user janek(uid=1008) by (uid=0)
Nov 24 14:40:24 main.iridion.it systemd[302939]: Failed to determine supported controllers: No such process
Nov 24 14:40:24 main.iridion.it systemd[302939]: Failed to allocate manager object: No such process
Nov 24 14:40:24 main.iridion.it systemd[1]: [email protected]: Main process exited, code=exited, status=1/FAILURE
Nov 24 14:40:24 main.iridion.it systemd[302940]: pam_unix(systemd-user:session): session closed for user janek
Nov 24 14:40:24 main.iridion.it systemd[1]: [email protected]: Failed with result 'exit-code'.
Nov 24 14:40:24 main.iridion.it systemd[1]: Failed to start User Manager for UID 1008.
2

I don’t think we run any user services so it must be done by the OS…

root@dev:~# systemctl status user@1000
○ [email protected] - User Manager for UID 1000
     Loaded: loaded (/lib/systemd/system/[email protected]; static)
    Drop-In: /usr/lib/systemd/system/[email protected]
             └─10-login-barrier.conf
     Active: inactive (dead)
       Docs: man:[email protected](5)