anchor.diff:  
       # Ensure all dependencies are in PATH
       wrapProgram $out/bin/pass \
  -      --prefix PATH : "${coreutils}/bin:${gnused}/bin:${getopt}/bin:${gnupg}/bin:${git}/bin:${tree}/bin:${pwgen}/bin${if withX then ":${xclip}/bin" else ""}"
  +      --prefix PATH : "${coreutils}/bin:${gnused}/bin:${getopt}/bin:${gnupg}/bin:${git}/bin:${tree}/bin:${pwgen}/bin${if x11Support then ":${xclip}/bin" else ""}"
   
  -    ${if withX then ''
  +    ${if x11Support then ''
         wrapProgram $out/bin/passmenu \
           --prefix PATH : "$out/bin:${xdotool}/bin:${dmenu}/bin"
       '' else ""}
  
positive.code: { stdenv, fetchurl
  , coreutils, gnused, getopt, pwgen, git, tree, gnupg
  , makeWrapper
  , withX ? true, xclip, xdotool, dmenu
  }:
  
  assert withX -> xclip != null;
  assert withX -> xdotool != null;
  assert withX -> dmenu != null;
  
  stdenv.mkDerivation rec {
    version = "1.6.5";
  
negative.code:     mkdir -p "$out/share/emacs/site-lisp"
      cp "contrib/emacs/password-store.el" "$out/share/emacs/site-lisp/"
  
      ${if x11Support then ''
        cp "contrib/dmenu/passmenu" "$out/bin/"
      '' else ""}
    '';
  