anchor.diff:      owner = "libxc";
       repo = "libxc";
       rev = version;
  -    sha256 = "1bcj7x0kaal62m41v9hxb4h1d2cxs2ynvsfqqg7c5yi7829nvapb";
  +    sha256 = "14czspifznsmvvix5hcm1rk18iy590qk8p5m00p0y032gmn9i2zj";
     };
   
     buildInputs = [ gfortran ];
  
positive.code:   '';
  
    doCheck = true;
    enableParallelBuilding = true;
  
    meta = with lib; {
      description = "Library of exchange-correlation functionals for density-functional theory";
  
negative.code: { lib, stdenv, fetchFromGitLab, cmake, gfortran, perl }:
  
  let
    version = "5.1.3";
  
  in stdenv.mkDerivation {
    pname = "libxc";
  