https://bugzilla.redhat.com/show_bug.cgi?id=984700
--- Comment #15 from Rex Dieter rdieter@math.unl.edu --- Per
Jul 22 08:13:18 nbecker1 sddm[27151]: DAEMON: Adding cookie to "/var/run/xauth/A:0-CiEIvq" Jul 22 08:13:18 nbecker1 sddm[27151]: /usr/bin/xauth: file /var/run/xauth/A:0-CiEIvq does not exist
Looks like you'll want to create/own this dir at least, though it may be wise to configure the defaults to use something sddm-specific, like: /var/run/sddm/ instead.
Anyway, see lightdm for an example of how to do this, http://pkgs.fedoraproject.org/cgit/lightdm.git/tree/lightdm.spec http://pkgs.fedoraproject.org/cgit/lightdm.git/tree/lightdm-tmpfiles.conf