anchor.diff:  
   { lib, stdenv, pkgconfig, pango, perl, python2, python3, zip
   , libjpeg, zlib, dbus, dbus-glib, bzip2, xorg
  -, freetype, fontconfig, file, nspr, nss, libnotify
  +, freetype, fontconfig, file, nspr, nss, nss_3_53, libnotify
   , yasm, libGLU, libGL, sqlite, unzip, makeWrapper
   , hunspell, libXdamage, libevent, libstartup_notification
   , libvpx_1_8
  
positive.code:   # 78 ESR won't build with rustc 1.47
    inherit (if lib.versionAtLeast ffversion "82" then rustPackages else rustPackages_1_45)
      rustc cargo;
  in
  
  buildStdenv.mkDerivation ({
  
negative.code: 
    NIX_CFLAGS_COMPILE = toString [
      "-I${glib.dev}/include/gio-unix-2.0"
      "-I${nss_pkg.dev}/include/nss"
    ];
  
    MACH_USE_SYSTEM_PYTHON = "1";
  