anchor.diff:  with stdenv.lib;
   
   stdenv.mkDerivation rec {
  -  version = "2.3.0";
     name = "gdal-${version}";
  +  version = "2.3.1";
   
     src = fetchurl {
       url = "https://download.osgeo.org/gdal/${version}/${name}.tar.xz";
  -    sha256 = "18iaamzkn0lipizynvspf3bs5qzgcy36hn6bbi941q8dlfdf8xbg";
  +    sha256 = "0nkjnznrp7dr41zsh8j923c9zpc3i5vj3wjfc2df9rrybb22ailw";
     };
   
  -  patches = [
  -    # fix build with recent Poppler
  -    (fetchpatch {
  -      url    = "https://github.com/OSGeo/gdal/commit/124f0343436d1267319ac627fc220530091b41ea.diff";
  -      stripLen = 2;
  -      extraPrefix = "";
  -      sha256 = "1v6iiy4cgrdcfas3iva5swh9446pqfjh5p6bcab6y49hyjhpsgfy";
  -    })
  -  ];
  -
     buildInputs = [ unzip libjpeg libtiff libpng proj openssl sqlite
  -    libspatialite poppler hdf4 ]
  +    libspatialite poppler hdf4 qhull giflib ]
     ++ (with pythonPackages; [ python numpy wrapPython ])
     ++ stdenv.lib.optional stdenv.isDarwin libiconv
     ++ stdenv.lib.optionals netcdfSupport [ netcdf hdf5 curl ];
  
positive.code: { stdenv, fetchurl, fetchpatch, unzip, libjpeg, libtiff, zlib
  , postgresql, mysql, libgeotiff, pythonPackages, proj, geos, openssl
  , libpng, sqlite, libspatialite, poppler, hdf4
  , libiconv
  , netcdfSupport ? true, netcdf, hdf5 , curl
  }:
  
negative.code:     "--with-sqlite3=${sqlite.dev}"
      "--with-spatialite=${libspatialite}"
      "--with-python"               # optional
      "--with-proj4=${proj}" # optional
      "--with-geos=${geos}/bin/geos-config"# optional
      "--with-hdf4=${hdf4.dev}" # optional
      (if netcdfSupport then "--with-netcdf=${netcdf}" else "")
  