anchor.diff:    additionalBackends = pkgs.stdenv.mkDerivation {
       name = "additional-cups-backends";
       builder = pkgs.writeScript "additional-backends-builder.sh" ''
  -      ${pkgs.coreutils}/bin/mkdir -p $out/lib/cups/backend
  -      ${pkgs.coreutils}/bin/ln -s ${pkgs.samba}/bin/smbspool $out/lib/cups/backend/smb
  +      PATH=${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.
  -      ${pkgs.coreutils}/bin/ln -s ipp $out/lib/cups/backend/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
       '';
     };
   
  
positive.code:       '';
  
    };
    
  }
  
negative.code:       };
  
      services.printing.drivers = [ pkgs.cups pkgs.ghostscript additionalBackends ];
      services.printing.cupsdConf =
        ''
          LogLevel info
  
  