Hi,

after adding: "service redshift" to my config.scm

running

sudo guix system configure /etc/config.scm

it says:

guix system: Fehler: _: bad use of '_' syntactic keyword

german Fehler = mistake

I don’t know where is my mistake.
................................................................................
here my config.scm:

;; This is an operating system configuration generated
;; by the graphical installer.

(use-modules (gnu))
(use-package-modules cups scanner)
(use-service-modules cups desktop networking ssh xorg virtualization)

(operating-system
   (locale "de_DE.utf8")
   (timezone "Europe/Berlin")
   (keyboard-layout (keyboard-layout "de"))
   (host-name "Tuxedo")
   (users (cons* (user-account
                   (name "gfp")
                   (comment "Gfp")
                   (group "users")
                   (home-directory "/home/gfp")
                   (supplementary-groups
                     '("wheel" "netdev" "audio" "video" "libvirt")))
                 %base-user-accounts))
   (packages
     (append
       (list (specification->package "nss-certs"))			
       %base-packages))
   (services
     (append
       (list (service mate-desktop-service-type)
             (service enlightenment-desktop-service-type)
			(service cups-service-type
				(cups-configuration
					(web-interface? #t)
					(extensions (list cups-filters hplip))))			
			(service openssh-service-type)
             (service tor-service-type)
             (set-xorg-configuration
               (xorg-configuration
                (keyboard-layout keyboard-layout)))
             (service libvirt-service-type
                      (libvirt-configuration
                       (unix-sock-group "libvirt")
                       (tls-port "16555")))
             (service virtlog-service-type
                      (virtlog-configuration
                       (max-clients 1000)))
             (service home-redshift-service-type
                      (home-redshift-configuration
                       (location-provider 'manual)
                       (latitude 52.5)        ;northern hemisphere
                       (longitude 13.5)))     ;Berlin
             (modify-services %desktop-services
  	      (guix-service-type
                    config => (guix-configuration
                      (inherit config)
                      (extra-options (list "--gc-keep-derivations=yes" 
"--gc-keep-outputs=yes")))))
	    (sane-service-type _ => sane-backends))))

   (bootloader
     (bootloader-configuration
       (bootloader grub-efi-bootloader)
       (targets (list "/boot/efi"))
       (keyboard-layout keyboard-layout)))
   (swap-devices
    (list (swap-space
           (target (uuid "51d5cd20-4513-4a02-9e35-df4338eccaa0")))))
   (file-systems
     (cons* (file-system
              (mount-point "/boot/efi")
              (device (uuid "BB77-FE3B" 'fat32))
              (type "vfat"))
            (file-system
              (mount-point "/")
              (device
                (uuid "4fb0ed7c-61ab-45eb-be0b-ff527b320e6d"
                      'ext4))
              (type "ext4"))
            %base-file-systems))
   (initrd-modules (cons "virtio_scsi"    ; Needed to find the disk
                         %base-initrd-modules)))

............................................................................ 

Thanks for help

Kind regards

Gottfried