anchor.diff:    meta = with stdenv.lib; {
       description = "A PostgreSQL/PostGIS extension that provides geospatial routing functionality";
       homepage    = "https://pgrouting.org/";
  +    changelog   = "https://github.com/pgRouting/pgrouting/releases/tag/v${version}";
       maintainers = [ maintainers.steve-chavez ];
       platforms   = postgresql.meta.platforms;
       license     = licenses.gpl2;
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "pgrouting";
    version = "3.1.0";
  
    nativeBuildInputs = [ cmake perl ];
    buildInputs = [ postgresql boost ];
  
negative.code:     owner  = "pgRouting";
      repo   = pname;
      rev    = "v${version}";
      sha256 = "1wj583c4iipsss75czww176aqa8sncsvcx1i0d6cb41v03iq5acf";
    };
  
    installPhase = ''
  