http://debian.ethz.ch/mirror/gnustep/GNUSTEP-raspberrypi-2.6.img.xz
$ xz -d GNUSTEP-raspberrypi-2.6.img.xz
# dd bs=4M if=GNUSTEP-raspberrypi-2.6.img of=/dev/mmcblk0
me@gnustep:~$ su
root@gnustep:/home/me# apt-get update
root@gnustep:/home/me# apt-get upgrade
root@gnustep:/home/me# passwd me
util01@station02:~$ ssh me@192.168.1.33
me@192.168.1.33's password:
Linux gnustep 4.9.41-v7+ #1023 SMP Tue Aug 8 16:00:15 BST 2017 armv7l
Welcome to GNUSTEP
if you get to read this, the automatic X session starting failed.
Login as root, type su - me, then startx
Last login: Tue Aug 29 16:42:16 2017
me@gnustep:~$ su
root@gnustep:/home/me#