anchor.diff:  { stdenv, fetchurl, glib, libxml2, pkgconfig
   , gnomeSupport ? true, libgnome_keyring, sqlite, glib_networking, gobjectIntrospection
  -, valaSupport ? true, vala_0_23
  +, valaSupport ? true, vala_0_32
   , libintlOrEmpty
   , intltool, python }:
   let
  
positive.code: 
    # glib_networking is a runtime dependency, not a compile-time dependency
    configureFlags = "--disable-tls-check"
      + stdenv.lib.optionalString (!valaSupport) " --enable-vala=no"
      + stdenv.lib.optionalString (valaSupport) " --enable-vala=yes"
      + stdenv.lib.optionalString (!gnomeSupport) " --without-gnome";
  
    NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin "-lintl";
  
negative.code:   outputs = [ "dev" "out" ];
  
    buildInputs = libintlOrEmpty ++ [ intltool python sqlite ]
      ++ stdenv.lib.optionals valaSupport [ vala_0_32 ];
    nativeBuildInputs = [ pkgconfig ];
    propagatedBuildInputs = [ glib libxml2 gobjectIntrospection ]
      ++ stdenv.lib.optionals gnomeSupport [ libgnome_keyring ];
  