anchor.diff:      rev = version;
       sha256 = "1lygz07va6hsv2vlx9zwz5d2n81rxsdhmh0pqxgj8n1bvb1rp0qw";
     };
  +
  +  makeFlags = concatStringsSep " " (
  +    optional (compiler != null) "compiler=${compiler}" ++
  +    optional (stdver != null) "stdver=${stdver}"
  +  );
   
     installPhase = ''
       mkdir -p $out/{lib,share/doc}
  
positive.code: 
    enableParallelBuilding = true;
  
    meta = with stdenv.lib; {
      description = "Intel Thread Building Blocks C++ Library";
      homepage = "http://threadingbuildingblocks.org/";
      license = licenses.asl20;
  
negative.code: { stdenv, fetchFromGitHub, compiler ? if stdenv.cc.isClang then "clang" else null, stdver ? null }:
  
  with stdenv.lib; stdenv.mkDerivation rec {
    name = "tbb-${version}";
    version = "2018_U1";
  
  