anchor.diff:    # cupsd.conf tells cupsd to use this tree.
     bindir = pkgs.buildEnv {
       name = "cups-progs";
  -    paths =  cfg.drivers;
  +    paths = cfg.drivers;
       pathsToLink = [ "/lib/cups" "/share/cups" ];
  -    postBuild =  ''
  -      ${cfg.bindirCmds}
  -    '';
  +    postBuild = cfg.bindirCmds;
     };
   
   in
  
positive.code:       };
  
      services.printing.drivers = [ pkgs.cups pkgs.ghostscript additionalBackends ];
      services.printing.cupsdConf = 
        ''
          LogLevel info
  
  
negative.code:   additionalBackends = pkgs.stdenv.mkDerivation {
      name = "additional-cups-backends";
      builder = pkgs.writeScript "additional-backends-builder.sh" ''
        PATH=${pkgs.coreutils}/bin
        mkdir -p $out
        if [[ ! -e ${pkgs.samba}/lib/cups/backend/smb ]]; then
          mkdir -p $out/lib/cups/backend
          ln -s ${pkgs.samba}/bin/smbspool $out/lib/cups/backend/smb
        fi
  
        # Provide support for printing via HTTPS.
        if [[ ! -e ${pkgs.cups}/lib/cups/backend/https ]]; then
          mkdir -p $out/lib/cups/backend
          ln -s ipp $out/lib/cups/backend/https
        fi
      '';
    };
  
  