Weston fails to start via systemd in QEMU x86-64

weston.service - Weston reference Wayland compositor
   Loaded: loaded (/lib/systemd/system/weston.service; disabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2017-07-27 14:36:59 UTC; 10s ago
  Process: 273 ExecStop=/usr/bin/killall -s KILL weston (code=exited, status=1/FAILURE)
  Process: 191 ExecStart=/usr/bin/weston-launch -u root -- --idle-time=4294967 (code=exited, status=1/FAILURE)
 Main PID: 191 (code=exited, status=1/FAILURE)

Jul 27 14:36:57 qemux86-64 systemd[1]: Started Weston reference Wayland compositor.
Jul 27 14:36:58 qemux86-64 weston-launch[191]: mpam_lastlog(login:session): file /var/log/lastlog created
Jul 27 14:36:58 qemux86-64 weston-launch[191]: pam_unix(login:session): session opened for user root by (uid=0)
Jul 27 14:36:59 qemux86-64 systemd[1]: mweston.service: Main process exited, code=exited, status=1/FAILURE
Jul 27 14:36:59 qemux86-64 killall[273]: killall: weston: no process killed
Jul 27 14:36:59 qemux86-64 systemd[1]: mweston.service: Control process exited, code=exited status=1
Jul 27 14:36:59 qemux86-64 systemd[1]: mweston.service: Unit entered failed state.
Jul 27 14:36:59 qemux86-64 systemd[1]: mweston.service: Failed with result 'exit-code'.

root@qemux86-64:~# /usr/bin/weston-launch -u root -- --idle-time=4294967
Date: 2017-07-27 UTC
[14:39:18.523] weston 1.11.0
               http://wayland.freedesktop.org
               Bug reports to: https://bugs.freedesktop.org/enter_bug.cgi?product=Wayland&component=weston&version=1.11.0
               Build: 1.10.93-2-g2d825ed configure.ac: bump to version 1.11.0 for the official release (2016-05-31 17:10:40 -0700)
[14:39:18.524] OS: Linux, 4.8.12-yocto-standard, #1 SMP PREEMPT Mon Jul 24 16:06:40 CEST 2017, x86_64
[14:39:18.524] fatal: environment variable XDG_RUNTIME_DIR is not set.
Refer to your distribution on how to get it, or
http://www.freedesktop.org/wiki/Specifications/basedir-spec
on how to implement it.
failed to restore keyboard mode: Bad file descriptor
failed to set KD_TEXT mode on tty: Bad file descriptor
could not reset vt handling

root@qemux86-64:~# env
XDG_SESSION_ID=c2
TERM=xterm-256color
SHELL=/bin/sh
SSH_CLIENT=10.0.2.2 50458 22
SSH_TTY=/dev/pts/0
USER=root
MAIL=/var/mail/root
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin
PWD=/home/root
EDITOR=vi
NODE_PATH=/usr/lib/node_modules/
PS1=\u@\h:\w\$ 
SHLVL=1
HOME=/home/root
LOGNAME=root
SSH_CONNECTION=10.0.2.2 50458 10.0.2.15 22
XDG_RUNTIME_DIR=/run/user/0
_=/usr/bin/env