anchor.diff:    buildInputs = [
       cups poppler poppler_utils fontconfig libjpeg libpng perl
       ijs qpdf dbus avahi ghostscript mupdf
  +    liblouis # braille embosser support
     ];
   
     configureFlags = [
  
positive.code: { lib, stdenv, fetchurl, pkg-config, cups, poppler, poppler_utils, fontconfig
  , libjpeg, libpng, perl, ijs, qpdf, dbus, avahi
  , makeWrapper, coreutils, gnused, bc, gawk, gnugrep, which, ghostscript
  , mupdf
  }:
  
  let
  
negative.code: 
  in stdenv.mkDerivation rec {
    pname = "cups-filters";
    version = "1.28.10";
  
    src = fetchurl {
      url = "https://openprinting.org/download/cups-filters/${pname}-${version}.tar.xz";
      sha256 = "sha256-z4yQRpTETPaJtXJORtI9qa5RJdVDdLNAxkIHfMKcqDc=";
    };
  
    nativeBuildInputs = [ pkg-config makeWrapper ];
  