anchor.diff:        # old versions are at the url below
         "https://pari.math.u-bordeaux.fr/pub/pari/OLD/${lib.versions.majorMinor version}/${pname}-${version}.tar.gz"
       ];
  -    hash = "sha256-zLp/FgbGhU8UQ2N7tXrQlY1Bx/R1P4roRZ8dZMJnoco=";
  +    hash = "sha256-vN6ezq4VkoFDgcFpfNtwY1Z7ZQQgGxvke7WJIPO84YU=";
     };
   
     buildInputs = [
  
positive.code:     license = licenses.gpl2Plus;
      maintainers = with maintainers; [ ertes AndersonTorres ] ++ teams.sage.members;
      platforms = platforms.linux ++ platforms.darwin;
    };
  }
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "pari";
    version = "2.13.4";
  
    src = fetchurl {
      urls = [
  