The user run directory is not created on the host.
However, I figured out what’s going on. If login with my unprivileged user the directory is auto-created. If I login with ‘su -l’ it isn’t and no Systemd user session is created:
#su -l <user>
systemctl --user status
Failed to connect to bus: No such file or directory
Some Googling indicates this is controlled by configuration in /etc/pam.d.
#cat /etc/pam.d/su-l
#%PAM-1.0
auth include su
account include su
password include su
session optional pam_keyinit.so force revoke
session include su
I’m not familiar with these settings but it appears su -l should start a user session.
In any case, now that I know to login directly I’m happy.