anchor.diff:  { stdenv, fetchurl, composableDerivation, unzip, libjpeg, libtiff, zlib
  -, postgresql, mysql, libgeotiff, python, pythonPackages, proj, geos, openssl
  -, libpng }:
  +, postgresql, mysql, libgeotiff, proj, geos, openssl
  +, libpng
  +# disabling python for now
  +# , python, pythonPackages
  +}:
   
   composableDerivation.composableDerivation {} (fixed: rec {
     version = "1.11.2";
  
positive.code:     "--with-pg=${postgresql}/bin/pg_config"
      "--with-mysql=${mysql.lib}/bin/mysql_config"
      "--with-geotiff=${libgeotiff}"
      "--with-python"               # optional
      "--with-static-proj4=${proj}" # optional
      "--with-geos=${geos}/bin/geos-config"# optional
    ];
  
    meta = {
  
negative.code:     sha256 = "66bc8192d24e314a66ed69285186d46e6999beb44fc97eeb9c76d82a117c0845";
    };
  
    buildInputs = [ unzip libjpeg libtiff libpng proj openssl ]
      # ++ [ python pythonPackages.numpy ]
    ;
  
    # Don't use optimization for gcc >= 4.3. That's said to be causing segfaults.
    # Unset CC and CXX as they confuse libtool.
  