anchor.diff:      platforms   = platforms.all;
     };
   }
  -
  
positive.code: { stdenv, fetchFromGitHub, cmake, pkgconfig, boost, blas
  , Accelerate, CoreGraphics, CoreVideo
  }:
  
  
negative.code:   ];
  
    nativeBuildInputs = [ pkgconfig cmake ];
    buildInputs = [ boost lapack ]
      ++ stdenv.lib.optionals stdenv.isDarwin [ Accelerate CoreGraphics CoreVideo ];
  
    enableParallelBuilding = true;
  