anchor.diff:    FONTCONFIG_FILE = makeFontsConf {
       fontDirectories = [
         gentium
  -      gentium-book-basic
  -      dejavu_fonts
       ];
     };
   
  
positive.code: { stdenv, darwin, fetchurl, makeWrapper, pkgconfig
  , harfbuzz, icu
  , fontconfig, lua, libiconv
  , makeFontsConf, gentium, gentium-book-basic, dejavu_fonts
  }:
  
  with stdenv.lib;
  
  let
    luaEnv = lua.withPackages(ps: with ps;[ lpeg luaexpat lua-zlib luafilesystem luasocket luasec]);
  
  in
  
  stdenv.mkDerivation rec {
    pname = "sile";
    version = "0.9.5.1";
  
    src = fetchurl {
      url = "https://github.com/simoncozens/sile/releases/download/v${version}/${pname}-${version}.tar.bz2";
      sha256 = "0fh0jbpsyqyq0hzq4midn7yw2z11hqdgqb9mmgz766cp152wrkb0";
    };
  
    nativeBuildInputs = [pkgconfig makeWrapper];
  
negative.code:   enableParallelBuilding = true;
  
    checkPhase = ''
      make documentation examples
    '';
  
    postInstall = ''
      install -D -t $out/share/doc/sile documentation/sile.pdf
      install -D -t $out/share/doc/sile examples
    '';
  
    # Hack to avoid TMPDIR in RPATHs.
  