Actually, I think it should be the higher-level sexp:

  #$(this-package-input "perl-archive-zip")

How can one know, this one to use?

The blog post is more like a historical story, not a tutorial for converting. It uses both

           #~`("--disable-color"
               ,(string-append "--with-gawk=" #$gawk))))

and

           #~(list (string-append "--with-gawk="
                                  #$(this-package-input "gawk")))))

The manual seems to mostly use the former way.

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |