Set XAUTHLOCALHOSTNAME in systemd user session, or starting of systemd-activated
services will fail.
Observed on openSUSE-Tumbleweed-Rescue-CD-x86_64-Snapshot20171213-Media.iso

Index: b/scripts/xinitrc.in
===================================================================
--- a/scripts/xinitrc.in
+++ b/scripts/xinitrc.in
@@ -86,6 +86,10 @@ cat /dev/null $XRESOURCES | xrdb -nocpp
 # load local modmap
 test -r $HOME/.Xmodmap && xmodmap $HOME/.Xmodmap
 
+# if XAUTHLOCALHOSTNAME is not set in systemd user session, starting of xfce4-notifyd etc. will fail
+if systemctl --user list-jobs >/dev/null 2>&1; then # user session is running
+  dbus-update-activation-environment --systemd XAUTHLOCALHOSTNAME=$XAUTHLOCALHOSTNAME
+fi
 # check if we start xfce4-session with ck-launch-session. this is only
 # required for starting from a console, not a login manager
 if test "x$XFCE4_SESSION_WITH_CK" = "x1"; then
Index: b/scripts/xinitrc.in.in
===================================================================
--- a/scripts/xinitrc.in.in
+++ b/scripts/xinitrc.in.in
@@ -86,6 +86,10 @@ cat /dev/null $XRESOURCES | xrdb -nocpp
 # load local modmap
 test -r $HOME/.Xmodmap && xmodmap $HOME/.Xmodmap
 
+# if XAUTHLOCALHOSTNAME is not set in systemd user session, starting of xfce4-notifyd etc. will fail
+if systemctl --user list-jobs >/dev/null 2>&1; then # user session is running
+  dbus-update-activation-environment --systemd XAUTHLOCALHOSTNAME=$XAUTHLOCALHOSTNAME
+fi
 # check if we start xfce4-session with ck-launch-session. this is only
 # required for starting from a console, not a login manager
 if test "x$XFCE4_SESSION_WITH_CK" = "x1"; then