anchor.diff:    buildInputs = [
       SDL2
       curl
  +    duktape
       fontconfig
       freetype
       icu
       jansson
  +    libGLU
       libiconv
       libpng
       libpthreadstubs
       libzip
  -    libGLU
       openssl
       speexdsp
       zlib
  
positive.code: 
    postUnpack = ''
      cp -r ${objects-src}         $sourceRoot/data/object
      cp -r ${title-sequences-src} $sourceRoot/data/title
    '';
  
    cmakeFlags = [
  
negative.code: { stdenv, fetchFromGitHub
  , SDL2, cmake, curl, duktape, fontconfig, freetype, icu, jansson, libGLU
  , libiconv, libpng, libpthreadstubs, libzip, openssl, pkgconfig, speexdsp, zlib
  }:
  
  let
    version = "0.3.0";
  
    openrct2-src = fetchFromGitHub {
      owner = "OpenRCT2";
      repo = "OpenRCT2";
      rev = "v${version}";
      sha256 = "0xs8pnn3lq30iy76pv42hywsrabapcrrkl597dhjafwh1xaxxj91";
    };
  
    objects-src = fetchFromGitHub {
      owner = "OpenRCT2";
      repo = "objects";
      rev = "v1.0.16";
      sha256 = "1xz50ghiqj9rm0m6d65j09ich6dlhyj36zah6zvmmzr4kg6svnk5";
    };
  
    title-sequences-src = fetchFromGitHub {
  