anchor.diff:      mkdir -p $out/lib/pkgconfig
       cp glew*.pc $out/lib/pkgconfig
       cp -r README.txt LICENSE.txt doc $out/share/doc/glew
  +    rm $out/lib/*.a
     '';
   
     crossAttrs.makeFlags = [
  
positive.code:   installFlags = [ "install.all" ];
  
    preInstall = ''
      export GLEW_DEST="$out"
    '';
  
    postInstall = ''
  
negative.code:     url = "mirror://sourceforge/glew/${name}.tgz";
      sha256 = "1iwb2a6wfhkzv6fa7zx2gz1lkwa0iwnd9ka1im5vdc44xm4dq9da";
    };
  
    outputs = [ "bin" "out" "dev" "doc" ];
  
    nativeBuildInputs = [ xlibsWrapper libXmu libXi ];
    propagatedNativeBuildInputs = [ mesa_glu ]; # GL/glew.h includes GL/glu.h
  