anchor.diff:      "-DCMAKE_INSTALL_INCLUDEDIR=include"
       "-Dalien=OFF"
       "-Dbonjour=OFF"
  +    "-Dbuiltin_llvm=OFF"
       "-Dcastor=OFF"
       "-Dchirp=OFF"
       "-Dclad=OFF"
  
positive.code:   };
  
    nativeBuildInputs = [ makeWrapper cmake pkgconfig ];
    buildInputs = [ ftgl gl2ps glew pcre zlib zstd libxml2 lz4 lzma gsl xxHash libAfterImage giflib libjpeg libtiff libpng python.pkgs.numpy ]
      ++ lib.optionals (!stdenv.isDarwin) [ libX11 libXpm libXft libXext libGLU libGL ]
      ++ lib.optionals (stdenv.isDarwin) [ Cocoa OpenGL ]
      ;
  
negative.code: { stdenv, lib, fetchurl, makeWrapper, cmake, ftgl, gl2ps, glew, gsl, llvm_5
  , libX11, libXpm, libXft, libXext, libGLU, libGL, libxml2, lz4, lzma, pcre
  , pkgconfig, python, xxHash, zlib, zstd
  , libAfterImage, giflib, libjpeg, libtiff, libpng
  , Cocoa, OpenGL, noSplash ? false }:
  
  