Define a service for dunst to start up when I log in.

#+begin_src scheme
  (define dunst
    (make <service>
      #:provides '(dunst)
      #:docstring "Notification daemon"
      #:start (make-forkexec-constructor
               '("dunst")
               #:log-file (string-append (getenv "HOME") "/.logs/dunst.log"))
      #:stop (make-kill-destructor)))

  (register-services dunst)

  (start dunst)
#+end_src