anchor.diff:    };
   
     nativeBuildInputs = [ makeWrapper cmake pkgconfig ];
  -  buildInputs = [ ftgl gl2ps glew pcre zlib zstd libxml2 lz4 lzma gsl xxHash libAfterImage giflib libjpeg libtiff libpng python.pkgs.numpy ]
  +  buildInputs = [ ftgl gl2ps glew pcre zlib zstd llvm_5 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 ]
       ;
  
positive.code:     "-DCMAKE_INSTALL_INCLUDEDIR=include"
      "-Dalien=OFF"
      "-Dbonjour=OFF"
      "-Dcastor=OFF"
      "-Dchirp=OFF"
      "-Dclad=OFF"
  
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 }:
  
  