anchor.diff:    tests = dbus_drv "tests" "test" {
       preBuild = makeInternalLib;
       buildInputs = buildInputsX ++ systemdOrEmpty ++ [ libs tools daemon dbus_glib python ];
  -    NIX_CFLAGS_LINK = "-Wl,--as-needed -ldbus-1";
  +    NIX_CFLAGS_LINK = 
  +      stdenv.lib.optionalString (!stdenv.isDarwin) "-Wl,--as-needed "
  +      + "-ldbus-1";
     };
   
     docs = dbus_drv "docs" "doc" {
  
positive.code:   tools = dbus_drv "tools" "tools" {
      configureFlags = [ "--with-dbus-daemondir=${daemon}/bin" ];
      buildInputs = buildInputsX ++ systemdOrEmpty ++ [ libs daemon dbus_glib ];
      NIX_CFLAGS_LINK = "-Wl,--as-needed -ldbus-1";
  
      meta.platforms = stdenv.lib.platforms.all;
    };
  
negative.code: { stdenv, fetchurl, pkgconfig, autoconf, automake, libtool
  , expat, systemd, glib, dbus_glib, python
  , libX11, libICE, libSM, useX11 ? (stdenv.isLinux || stdenv.isDarwin) }:
  
  let
    version = "1.6.12"; # 1.7.* isn't recommended, even for gnome 3.8
  