anchor.diff:      owner  = "pgRouting";
       repo   = pname;
       rev    = "v${version}";
  -    sha256 = "0sdyq0a98snmcq6g6mgmadlz6cgvacivv34943azhnzspa3iy409";
  +    sha256 = "1wj583c4iipsss75czww176aqa8sncsvcx1i0d6cb41v03iq5acf";
     };
   
     installPhase = ''
  
positive.code:   meta = with stdenv.lib; {
      description = "A PostgreSQL/PostGIS extension that provides geospatial routing functionality";
      homepage    = "https://pgrouting.org/";
      maintainers = [ maintainers.steve-chavez ];
      platforms   = postgresql.meta.platforms;
      license     = licenses.gpl2;
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "pgrouting";
    version = "3.1.1";
  
    nativeBuildInputs = [ cmake perl ];
    buildInputs = [ postgresql boost ];
  