define udev-service-type fails with "did you forget to import.." error

[Stefan Huchler]

When I try to redefine the udev-service like described in:
https://guix.gnu.org/manual/en/html_node/Service-Types-and-Services.html


(define udev-service-type
  (service-type (name 'udev)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          udev-shepherd-service)))
                (compose concatenate)       ;concatenate the list of rules
                (extend (lambda (config rules)
                          (match config
                            (($ <udev-configuration> udev initial-rules)
                             (udev-configuration
                              (udev eudev)   ;the udev package to use
                              (rules initial-rules))))))))

I get following error:
/etc/config.scm:128:0: error: udev-shepherd-service: unbound variable
hint: Did you forget `(use-modules (gnu services base))'?

Despite having:
(use-modules (gnu services base)...)

Any Idea what I do wrong?


btw I removed the append part of rules
otherwise it's copied from that docu example.