anchor.diff:      description = "A high quality educational software suite, including a large number of activities for children aged 2 to 10";
       homepage = "https://gcompris.net/";
       license = licenses.gpl3Plus;
  +    mainProgram = "gcompris-qt";
       maintainers = with maintainers; [ guibou ];
       platforms = platforms.linux;
     };
  
positive.code:   nativeBuildInputs = [ cmake gettext ninja qttools ];
  
    buildInputs = [
      qmlbox2d qtbase qtdeclarative qtgraphicaleffects qtmultimedia qtquickcontrols qtsensors qtxmlpatterns
    ] ++ (with gst_all_1; [
      gstreamer gst-plugins-base gst-plugins-good gst-plugins-bad
    ]);
  
    postInstall = ''
      install -Dm444 ../org.kde.gcompris.desktop        $out/share/applications/gcompris.desktop
      install -Dm444 ../images/256-apps-gcompris-qt.png $out/share/icons/hicolor/256x256/apps/gcompris-qt.png
      install -Dm444 ../org.kde.gcompris.appdata.xml -t $out/share/metainfo
  
      qtWrapperArgs+=(--prefix GST_PLUGIN_SYSTEM_PATH_1_0 : "$GST_PLUGIN_SYSTEM_PATH_1_0")
    '';
  
negative.code: 
  mkDerivation rec {
    pname = "gcompris";
    version = "2.3";
  
    src = fetchurl {
      url = "https://download.kde.org/stable/gcompris/qt/src/gcompris-qt-${version}.tar.xz";
      sha256 = "sha256-UgWLp5IVqbeFFCO/PRFJ/X1sPm7nSkagVcgEp5SdzGI=";
    };
  
    cmakeFlags = [
  