anchor.diff:  { stdenv, fetchFromGitHub, pam, pkgconfig, autoconf, automake, libtool, libxcb
   , glib, libXdmcp, itstool, intltool, libxklavier, libgcrypt, audit, busybox
  -, polkit, accountsservice, gtk-doc, gnome3, gobject-introspection, vala
  +, polkit, accountsservice, gtk-doc, gnome3, gobject-introspection, vala, fetchpatch
   , withQt4 ? false, qt4
   , withQt5 ? false, qtbase
   }:
  
positive.code:   ] ++ optional withQt4 qt4
      ++ optional withQt5 qtbase;
  
    patches = [ ./run-dir.patch ];
  
    preConfigure = "NOCONFIGURE=1 ./autogen.sh";
  
  
negative.code: 
    meta = {
      homepage = https://github.com/CanonicalLtd/lightdm;
      description = "A cross-desktop display manager";
      platforms = platforms.linux;
      license = licenses.gpl3;
      maintainers = with maintainers; [ ocharles worldofpeace ];
  