Comment # 8 on bug 932787 from Arun Persaud

Traced the problem back to /etc/gdm/Xsession (in current tumbleweed).
Here, the first lines are:

if test -x /etc/X11/xdm/Xsession; then
       exec /etc/X11/xdm/Xsession $1 $GDM_LANG
fi

If I delete the $GDM_LANG i3 starts again.