anchor.diff: -{ lib, stdenv, fetchsvn, pkgconfig, libjpeg, libpng, flex, zlib, perl, libxml2
  -, makeWrapper, libtiff
  -, enableX11 ? false, libX11 }:
  +{ lib
  +, stdenv
  +, fetchsvn
  +, pkgconfig
  +, libjpeg
  +, libpng
  +, flex
  +, zlib
  +, perl
  +, libxml2
  +, makeWrapper
  +, libtiff
  +, enableX11 ? false
  +, libX11
  +}:
   
   stdenv.mkDerivation {
     # Determine version and revision from:
  
positive.code:   passthru.updateScript = ./update.sh;
  
    meta = {
      homepage = http://netpbm.sourceforge.net/;
      description = "Toolkit for manipulation of graphic images";
      license = "GPL,free";
      platforms = with stdenv.lib.platforms; linux ++ darwin;
    };
  }
  
negative.code:       --replace '"-dSAFER"' '"-dPARANOIDSAFER"'
    '';
  
    nativeBuildInputs = [
      pkgconfig
      flex
      makeWrapper
    ];
  
    buildInputs = [
      zlib
      perl
      libpng
      libjpeg
      libxml2
      libtiff
    ] ++ lib.optional enableX11 libX11;
  
    configurePhase = ''
      cp config.mk.in config.mk
  