## Observation

The purpose of this test is to check how login managers work with many existing
users on a system.
Most login managers react on this by replacing the dropdown user selection menu
by a text field.
To do this, the existing X11/Wayland/Whatever is stopped. Then 100 users are
created and then
the graphical session is restarted.

This doesn't work anymore:

```
systemctl isolate multi-user.target
# create 100 users
systemctl isolate graphical.target
```

When the graphical target is isolated an error message is shown:
'Unable to contact settings server, Failed to connect to socket
/run/user/1000/bus'

openQA test in scenario
opensuse-Tumbleweed-DVD-x86_64-extra_tests_on_xfce@64bit fails in
[multi_users_dm](http://openqa.opensuse.org/tests/335702/modules/multi_users_dm/steps/26)

## Reproducible

Fails since Build [20170111](http://openqa.opensuse.org/tests/333055)

## Expected result

Last good: [20170110](http://openqa.opensuse.org/tests/332625)

## Further details

The issue has been triggered by starting the session D-Bus via systemd:
https://build.opensuse.org/package/rdiff/Base:System/dbus-1?linkrev=base&rev=236

It seems that pulseaudio and `spice-vdagent` are preventing the old session to
close. When starting also pulseaudio via systemd and killing `spice-vdagent`
before isolating the graphical target the issue doesn't occur.

I think starting D-Bus via systemd is the right thing to as it allows usage of
`busctl` for instance. It should be possible to reduce the problem by also
starting pulseaudio via systemd. Not sure about `spice-vdagent`, though.

Always latest result in this scenario:
[latest](http://openqa.opensuse.org/tests/latest?version=Tumbleweed&arch=x86_64&flavor=DVD&distri=opensuse&test=extra_tests_on_xfce&machine=64bit)

It also fails for KDE:
https://openqa.opensuse.org/tests/335701#step/multi_users_dm/26

## Workaround

Remove the symlink `/usr/lib/systemd/user/sockets.target.wants/dbus.socket` for
the old behavior (session
D-Bus no longer started via systemd).