anchor.diff:    # 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${version}";
  -    sha256 = "0abjm0wywp24qlgg9w8g35ijprjg5csq4fgba9caaiwvmpfbhmpw";
  +    rev = "v${version}";
  +    sha256 = "05zy6w9lwwh254wa8c6wysa67kk0flywcvipii9b1rmy47slflhs";
       fetchSubmodules = true;
     };
   
  -  meta = with stdenv.lib; {
  +  meta = with lib; {
       description = "Provides full ground station support and configuration for the PX4 and APM Flight Stacks";
  -    homepage = http://qgroundcontrol.org/;
  +    homepage = "http://qgroundcontrol.org/";
       license = licenses.gpl3Plus;
       platforms = platforms.linux;
       maintainers = with maintainers; [ pxc ];
  -    broken = true;
     };
   }
  
positive.code:   ];
  
    enableParallelBuilding = true;
    buildInputs = [ SDL2 udev doxygen git ] ++ gstInputs ++ qtInputs;
    nativeBuildInputs = [ pkgconfig makeWrapper qmake ];
  
    preConfigure = ''
  
negative.code: { lib, mkDerivation, fetchgit, SDL2
  , qtbase, qtcharts, qtlocation, qtserialport, qtsvg, qtquickcontrols2
  , qtgraphicaleffects, qtspeech, qmake
  , makeWrapper
  , gst_all_1, pkgconfig
  }:
  
  mkDerivation rec {
    pname = "qgroundcontrol";
    version = "3.5.5";
  
    qtInputs = [
      qtbase qtcharts qtlocation qtserialport qtsvg qtquickcontrols2
      qtgraphicaleffects qtspeech
    ];
  
    gstInputs = with gst_all_1; [
  