anchor.diff:  { lib, stdenv, fetchurl, fetchpatch, python, zlib, pkg-config, glib
   , perl, pixman, vde2, alsa-lib, texinfo, flex
   , bison, lzo, snappy, libaio, libtasn1, gnutls, nettle, curl, ninja, meson, sigtool
  -, makeWrapper, autoPatchelfHook
  +, makeWrapper
   , attr, libcap, libcap_ng
   , CoreServices, Cocoa, Hypervisor, rez, setfile
   , numaSupport ? stdenv.isLinux && !stdenv.isAarch32, numactl
  
positive.code: 
    configureFlags = [
      "--audio-drv-list=${audio}"
      "--enable-docs"
      "--enable-tools"
      "--enable-guest-agent"
  
negative.code: 
    nativeBuildInputs = [ makeWrapper python python.pkgs.sphinx python.pkgs.sphinx_rtd_theme pkg-config flex bison meson ninja ]
      ++ lib.optionals gtkSupport [ wrapGAppsHook ]
      ++ lib.optionals stdenv.isDarwin [ sigtool ];
  
    buildInputs = [ zlib glib perl pixman
  