anchor.diff:  
     src = fetchurl {
       url = "http://faculty.cse.tamu.edu/davis/SuiteSparse/SuiteSparse-${version}.tar.gz";
  -    sha256 = "0gcn1xj3z87wpp26gxn11k8073bxv6jswfd8jmddlm64v09rgrlh";
  +    sha256 = "1lfvjj787yqyhk25w7brlrkrl7dnnn5dq4ijxws3wrbcd4vd2k9p";
     };
   
     dontUseCmakeConfigure = true;
  
positive.code: { stdenv, fetchurl, gfortran, openblas, cmake, fixDarwinDylibNames
  , enableCuda  ? false, cudatoolkit
  }:
  
  let
    version = "5.3.0";
    name = "suitesparse-${version}";
  
    SHLIB_EXT = stdenv.hostPlatform.extensions.sharedLibrary;
  
negative.code:     runHook postInstall
      '';
  
    nativeBuildInputs = [
      cmake
      gnum4
    ] ++ stdenv.lib.optional stdenv.isDarwin fixDarwinDylibNames;
  
    buildInputs = [ openblas gfortran.cc.lib ]
      ++ stdenv.lib.optional enableCuda cudatoolkit;
  