anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "tracker";
  -  version = "3.4.0.alpha";
  +  version = "3.4.0.beta";
   
     outputs = [ "out" "dev" "devdoc" ];
   
     src = fetchurl {
       url = "mirror://gnome/sources/${pname}/${lib.versions.majorMinor version}/${pname}-${version}.tar.xz";
  -    sha256 = "PIbsVkHpSrf7gCut2BREyFSuT2MmIfvELUUgGRwyQGE=";
  +    sha256 = "r7evHXAHaELU6Fg691l6qJG9phTqiyjmAwiT/gxSpiE=";
     };
   
     postPatch = ''
  
positive.code:   nativeBuildInputs = [
      meson
      ninja
      vala
      pkg-config
      asciidoc
      gettext
  
negative.code: , libxml2
  , glib
  , wrapGAppsNoGuiHook
  , sqlite
  , libxslt
  , libstemmer
  