anchor.diff: -{ stdenv, fetchgit, git,  SDL2, udev, doxygen
  -, qtbase, qtlocation, qtserialport, qtdeclarative, qtconnectivity, qtxmlpatterns
  -, qtsvg, qtquick1, qtquickcontrols, qtgraphicaleffects, qmake, qtspeech
  +{ lib, mkDerivation, fetchgit, SDL2
  +, qtbase, qtcharts, qtlocation, qtserialport, qtsvg, qtquickcontrols2
  +, qtgraphicaleffects, qtspeech, qmake
   , makeWrapper
   , gst_all_1, pkgconfig
   }:
   
  -stdenv.mkDerivation rec {
  +mkDerivation rec {
     pname = "qgroundcontrol";
  -  version = "3.3.0";
  +  version = "3.5.5";
   
     qtInputs = [
  -    qtbase qtlocation qtserialport qtdeclarative qtconnectivity qtxmlpatterns qtsvg
  -    qtquick1 qtquickcontrols qtgraphicaleffects qtspeech
  +    qtbase qtcharts qtlocation qtserialport qtsvg qtquickcontrols2
  +    qtgraphicaleffects qtspeech
     ];
   
     gstInputs = with gst_all_1; [
  
positive.code:   # TODO: package mavlink so we can build from a normal source tarball
    src = fetchgit {
      url = "https://github.com/mavlink/qgroundcontrol.git";
      rev = "refs/tags/v${version}";
      sha256 = "0abjm0wywp24qlgg9w8g35ijprjg5csq4fgba9caaiwvmpfbhmpw";
      fetchSubmodules = true;
    };
  
    meta = with stdenv.lib; {
      description = "Provides full ground station support and configuration for the PX4 and APM Flight Stacks";
      homepage = http://qgroundcontrol.org/;
      license = licenses.gpl3Plus;
      platforms = platforms.linux;
      maintainers = with maintainers; [ pxc ];
      broken = true;
    };
  }
  
negative.code:   ];
  
    enableParallelBuilding = true;
    buildInputs = [ SDL2 ] ++ gstInputs ++ qtInputs;
    nativeBuildInputs = [ pkgconfig makeWrapper qmake ];
  
    preConfigure = ''
  