Comment 115 for bug 1197395

This is breaking tightvnc-server (F19), that starts the sessions via systemd with

ExecStart=/sbin/runuser -l <USER> -c "/usr/bin/vncserver ..."

Comment 34 explains very well why this is a bug, and Comment 35 offers a reasonable path to find a fix.

May be it is time to introduce a "--subsession" flag to "su", that works like "--login" plus the PAM/systemd calls needed to spawn the sub-session.

Lennart, you are blocking this bug because it hurts your design paradigm. The use cases exposed here were not taken into account when the design was done, it is time to integrate them. Your postulate "This can never fly" is a poor excuse, Linux gives us wings. Multi-user desktops have been working for ages, now they are broken. Please help us find a reasonable trade-off!