anchor.diff:      "av"
       "rgl"
       "NetLogoR"
  -    "proj4"
       "x13binary"
   
       # Impure network access during build
  
positive.code:     HDF5Array = [ pkgs.zlib.dev ];
      FLAMES = [ pkgs.zlib.dev ];
      ncdfFlow = [ pkgs.zlib.dev ];
    };
  
    packagesRequiringX = [
  
negative.code:     phytools = [ pkgs.which ];
      PKI = [ pkgs.openssl.dev ];
      png = [ pkgs.libpng.dev ];
      protolite = [ pkgs.protobuf ];
      R2SWF = with pkgs; [ zlib libpng freetype.dev ];
      RAppArmor = [ pkgs.libapparmor ];
  