anchor.diff:  freetype, fontconfig, dbus, libX11, xorg, libXi, libXcursor, libXdamage,
   libXrandr, libXcomposite, libXext, libXfixes, libXrender, libXtst,
   libXScrnSaver, nss, nspr, alsaLib, cups, expat, udev, wrapGAppsHook,
  -hicolor-icon-theme }:
  +hicolor-icon-theme, libuuid, at-spi2-core, at-spi2-atk }:
   
   let
     rpath = stdenv.lib.makeLibraryPath [
       alsaLib
  +    at-spi2-atk
  +    at-spi2-core
       atk
       cairo
       cups
  
positive.code:     gnome2.GConf
      gtk3
      pango
      libX11
      libXScrnSaver
      libXcomposite
  
negative.code: in
    stdenv.mkDerivation rec {
      pname = "mattermost-desktop";
      version = "4.3.1";
  
      src =
        if stdenv.hostPlatform.system == "x86_64-linux" then
          fetchurl {
            url = "https://releases.mattermost.com/desktop/${version}/${pname}-${version}-linux-x64.tar.gz";
            sha256 = "076nv5h6xscbw1987az00x493qhqgrli87gnn57zbvz0acgvlhfv";
          }
        else if stdenv.hostPlatform.system == "i686-linux" then
          fetchurl {
            url = "https://releases.mattermost.com/desktop/${version}/${pname}-${version}-linux-ia32.tar.gz";
            sha256 = "19ps9g8j6kp4haj6r3yfy4ma2wm6isq5fa8zlcz6g042ajkqq0ij";
          }
        else
          throw "Mattermost-Desktop is not currently supported on ${stdenv.hostPlatform.system}";
  