anchor.diff:  { stdenv
  +, autoconf
  +, automake
   , docbook_xml_dtd_412
   , docbook-xsl
  -, fetchurl
  +, fetchzip
  +, gtk-doc
   , intltool
  +, libtool
   , libxslt
   
   , glib
   , expat
   , pam
  -, spidermonkey_17
  +, spidermonkey_24
   , gobject-introspection
   , systemd_lib
   }:
   
  +let
  +  date = "2016-12-12";
  +  rev = "3272a988655c3236b55bad70e9a3af20857f384b";
  +in
   stdenv.mkDerivation rec {
  -  name = "polkit-0.113";
  +  name = "polkit-${date}";
   
  -  src = fetchurl {
  -    url = "http://www.freedesktop.org/software/polkit/releases/${name}.tar.gz";
  -    sha256 = "109w86kfqrgz83g9ivggplmgc77rz8kx8646izvm2jb57h4rbh71";
  +  src = fetchzip {
  +    version = 2;
  +    url = "https://cgit.freedesktop.org/polkit/snapshot/${rev}.tar.xz";
  +    multihash = "Qmba7Ei5AJTci1cDevcGmqVSdnboyQf2h9bXBzbQzCEV9b";
  +    sha256 = "877444a34b99d32f44acd9c8d8e65fc3281c632b0177358babe0ce916252f636";
     };
   
     nativeBuildInputs = [
  +    autoconf
  +    automake
       docbook_xml_dtd_412
       docbook-xsl
  +    gtk-doc
       intltool
  +    libtool
       libxslt
     ];
   
  
positive.code:   '';
  
    preConfigure = ''
      configureFlagsArray+=(
        "--with-systemdsystemunitdir=$out/etc/systemd/system"
      )
  
negative.code:     patchShebangs .
  
      # Get rid of a check to see if systemd is running to allow libsystemd linking
      sed '/does not.*systemd/s/.*/:/' -i configure.ac
  
      # polkit-agent-helper-1 is a setuid binary so remap the path in the codebase.
      sed -i 's,PACKAGE_PREFIX "/lib/polkit-1,"/var/setuid-wrappers,g' \
  