Unseting session environment variables breaks user dbus instances
Assigned to Xorg Project Team
This line in startx script:
which was introduced in commit c07501f6, breaks the new behaviour of pam_systemd which sets this environment variable to point to the user bus, so that applications relying on session bus do not need to spawn another instance and dbus-launch is no longer necessary.
With this line, those applications won't work properly.