On Thu, Dec 01 2016, ng0 wrote
> https://ptpb.pw/gQOZ.scm with this change it fails differently:

This is wrong again, but for a different reason. The 
`%desktop-services` must be the last argument to the `cons*` call.

You want it to look like this (assuming my formatting comes out at 
least a little bit okay):

  (services (cons* (gnome-desktop-service)
                   (tor-service)
                   (console-keymap-service "de")
		   (lsh-service)
		   (let ((spec-guix `((#:name . "guix")
				      (#:url . "git://git.savannah.gnu.org/guix.git")
				      (#:load-path . ".")
				      ;; Adapt to a valid absolute file name.
				      (#:file . "/.../cuirass/tests/gnu-system.scm")
				      (#:proc . hydra-jobs)
				      (#:arguments (subset . "hello"))
				      (#:branch . "master"))))

		     (cuirass-service #:config (cuirass-configuration
						(specifications (list spec-guix)))))
		   %desktop-services))