anchor.diff:    '';
   
     doCheck = true;
  -  enableParallelBuilding = true;
   
     meta = with lib; {
       description = "Library of exchange-correlation functionals for density-functional theory";
  
positive.code:     owner = "libxc";
      repo = "libxc";
      rev = version;
      sha256 = "1bcj7x0kaal62m41v9hxb4h1d2cxs2ynvsfqqg7c5yi7829nvapb";
    };
  
    buildInputs = [ gfortran ];
  
negative.code: { lib, stdenv, fetchFromGitLab, cmake, gfortran, perl }:
  
  let
    version = "5.1.3";
  
  in stdenv.mkDerivation {
    pname = "libxc";
  