Create package to add new files

[calcium via <help-guix@gnu.org>]

I tried using the procedures text-file* and plain-file but I can't manage to make it works.

Im trying to define a package that will be used to add files to cups, in the same ways taht the package brlaser add files. But no luck, every time I try to create a `plain-file` the build fails.

Help appreciated

(define-public
  add-my-filters-and-ppd
  (package/inherit
   brlaser
   (name "add-my-filters-and-ppd")
   (arguments
    `(#:phases
      (modify-phases
       %standard-phases
       ;; (delete 'configure) ;no 'configure' script
       (replace
        'install
        (lambda* (#:key outputs #:allow-other-keys)
                 ;; The package's Makefile doesn't provide an "install"
                 ;; rule so do it by ourselves.
                 (let ((filter-dir
                        (string-append (assoc-ref outputs "out")
                                       "/lib/cups/filter"))
                       (ppd-dir
                        (string-append (assoc-ref outputs "out")
                                       "/share/ppd/cupsfilters")))
                   ;; (install-file
                   ;;  (plain-file "brother_lpdwrapper_printer-model"
                   ;;              "ldwrapper string/content of file"))
                   ;; (install-file
                   ;;  (plain-file "brother-printer-model-cups-en.ppd"
                   ;;              ".ppd string/content of file")
                   ;;  ppd-dir)
                   )
                 #t)))))))