error setting console font in system.scm

[Fulbert]

  Hi Guixers,

  (define myself (guix-noob-user (not (programmer))))

  Trying to change console font with the following in "services" section
of my system configuration file :

----
…
  (services (append (list
        …
        (service console-font-service-type
          `(("tty3" . ,(file-append font-terminus 
"/share/consolefonts/ter-128n"))))
      ) %desktop-services))
…
----

which results in the following error when reconfiguring the system :

----
$ sudo guix system --dry-run reconfigure /etc/config.scm
guix system: error: service 'console-font-tty3' provided more than once
----

  I probably missunderstand something and/or ill-format the
configuration…?… Help appreciated.

  Below is the related [(guix) Base services] Texinfo section.

----
--scheme Variable: console-font-service-type
    Install the given fonts on the specified ttys (fonts are per
    virtual console on the kernel Linux).  The value of this service is
    a list of tty/font pairs.  The font can be the name of a font
    provided by the ‘kbd’ package or any valid argument to ‘setfont’,
    as in this example:
      `(("tty1" . "LatGrkCyr-8x16")
        ("tty2" . ,(file-append
                      font-tamzen
                      "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
        ("tty3" . ,(file-append
                      font-terminus
                      "/share/consolefonts/ter-132n"))) ; for HDPI
----