anchor.diff:  { fetchurl, stdenv, which, pkgconfig, makeWrapper, libxcb, xcbutilkeysyms
   , xcbutil, xcbutilwm, libstartup_notification, libX11, pcre, libev, yajl
  -, xcb-util-cursor, coreutils, perl, pango, perlPackages, xdummy, libxkbcommon }:
  +, xcb-util-cursor, coreutils, perl, pango, perlPackages, libxkbcommon
  +, xorgserver, xvfb_run }:
   
   stdenv.mkDerivation rec {
     name = "i3-${version}";
  -  version = "4.9.1";
  +  version = "4.10.1";
   
     src = fetchurl {
       url = "http://i3wm.org/downloads/${name}.tar.bz2";
  -    sha256 = "0hyw2rdxigiklqvv7fbhcdqdxkgcxvx56vk4r5v55l674zqfy3dp";
  +    sha256 = "1qjpbrfy5pnk5d0dh9zs96ppw3jwad1jcy529zy4ja68mdgz6b8b";
     };
   
     buildInputs = [
  
positive.code:     libstartup_notification libX11 pcre libev yajl xcb-util-cursor perl pango
      perlPackages.AnyEventI3 perlPackages.X11XCB perlPackages.IPCRun
      perlPackages.ExtUtilsPkgConfig perlPackages.TestMore perlPackages.InlineC
    ];
  
    postPatch = ''
  
negative.code: 
    checkPhase = stdenv.lib.optionalString (stdenv.system == "x86_64-linux")
    ''
      (cd testcases && xvfb-run ./complete-run.pl -p 1)
      ! grep -q '^not ok' testcases/latest/complete-run.log
    '';
  
  