anchor.diff: -{ fetchurl, stdenv, pkgconfig, gnome3, clutter, dbus, python3Packages, libxml2
  +{ fetchurl, stdenv, pkgconfig, gnome3, glib, gtk3, clutter, dbus, python3, libxml2
   , libxklavier, libXtst, gtk2, intltool, libxslt, at-spi2-core, autoreconfHook
   , wrapGAppsHook }:
   
   let
     pname = "caribou";
     version = "0.4.21";
  -  pythonEnv = python3Packages.python.withPackages ( ps: with ps; [ pygobject3 ] );
  +  pythonEnv = python3.withPackages ( ps: with ps; [ pygobject3 ] );
   in stdenv.mkDerivation rec {
     name = "${pname}-${version}";
   
  
positive.code:     sha256 = "0mfychh1q3dx0b96pjz9a9y112bm9yqyim40yykzxx1hppsdjhww";
    };
  
    nativeBuildInputs = [ pkgconfig intltool libxslt libxml2 autoreconfHook wrapGAppsHook ];
  
    buildInputs = with gnome3;
      [ glib gtk clutter at-spi2-core dbus pythonEnv python3Packages.pygobject3
        libXtst gtk2 ];
  
    propagatedBuildInputs = [ gnome3.libgee libxklavier ];
  
  
negative.code:   meta = with stdenv.lib; {
      description = "An input assistive technology intended for switch and pointer users";
      homepage = https://wiki.gnome.org/Projects/Caribou;
      license = licenses.lgpl21;
      maintainers = gnome3.maintainers;
      platforms = platforms.linux;
    };
  }
  