[gdm-list] gdm-simple-greeter...Error getting session id from systemd: No such file or directory

[tjoen <tjoen dds nl>]

System: LFS-like
Migrating from upstart to systemd. After recompiling packages
for systemd-suuport everything works except gdm

gdm-3.6.2 built with:
./configure --prefix=/usr --disable-static \
 --with-sysconfsubdir=X11/gdm --with-dmconfdir=X11/dm \
 --with-default-pam-config=lfs

That --prefix=/usr reads /usr/share/config.site:
sysconfdir=/etc
infodir=/usr/share/info
mandir=/usr/share/man
localstatedir=/var

systemd-197:
./configure --prefix=/usr --disable-static --with-rootprefix=/ \
 --with-rootlibdir=/lib --with-pamlibdir=/lib/security

dbus-1.6.8:
./configure --prefix=/usr --disable-static --localstatedir=/var

Is that --localstatedir=/var correct?

In my previous upstart system booting results in fallback-session.
With systemd only the blue striped background, no greeter.

# systemctl status gdm
...
mrt 18 15:08:49 localhost systemd[1]: Starting GNOME Display Manager...
mrt 18 15:08:49 localhost systemd[1]: Started GNOME Display Manager.
mrt 18 15:08:50 localhost gdm-simple-slave[3781]: WARNING: Failed to
 give slave programs access to the display. Trying to proceed.
mrt 18 15:08:51 localhost gdm-launch-environment][3793]: GLib-CRITICAL:
 g_variant_new_string: assertion `string != NULL' failed
mrt 18 15:08:51 localhost gdm-launch-environment][3793]: WARNING:
 GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name
 org.freedesktop.ConsoleKit was not provided by any .service files
mrt 18 15:08:52 localhost gnome-session[3799]: WARNING: Could not get
 session id for session. Check that logind is properly installed and
 pam_systemd is getting used at login.

/etc/pam.d/system-auth contains:
session         required        pam_systemd.so

mrt 18 15:08:52 localhost gnome-session[3799]: WARNING: Session
'gdm-shell' runnable check failed: Child process exited with code 1
mrt 18 15:08:53 localhost pulseaudio[3833]: [pulseaudio] 
...
mrt 18 15:08:55 localhost gdm-simple-greeter[3850]: WARNING: Unable to
 start greeter session: 
GDBus.Error:org.gtk.GDBus.UnmappedGError.Quark._gdm_5fdisplay_5ferror.Code2:
 Error getting session id from systemd: No such file or directory

Same error if I created symlink /run/dbus -> /var/run/dbus/

The string "Error getting session id from systemd" doesn't 
give hints in Google, only to the sourcecode

Something is wrong in my setup but where?