Comment # 3 on bug 1012213 from Stefan Seyfried

we discussed this further in an submitrequest on the build service (see the
comments) https://build.opensuse.org/request/show/442399

Just starting it from a script run via /etc/X11/xinit.d/ fixes the "simple
minimal x11" case, but spice-vdagent runs twice in "full-blown" sessions like
XFCE, GNOME, KDE.

xinit.d/* runs before the session is started, and I did not find any evidence
in the environment from which I would have been able to decide if spice-vdagent
should be started or not.

One suggestion was to always just start from xinit.d, but then the graphical
configuration tools of the desktops that configure which services to start can
no longer be used.

The only solution would be IMO to package the xinit.d script in an additional
subpackage which can be installed on minimal desktops but should not be
installed on "full" installations.