anchor.diff:  { stdenv, fetchurl, lib, iasl, dev86, pam, libxslt, libxml2, libX11, xproto, libXext
   , libXcursor, libXmu, qt4, libIDL, SDL, libcap, zlib, libpng, glib, kernel, lvm2
   , which, alsaLib, curl, libvpx, gawk
  -, xorriso, makeself, perl, pkgconfig
  +, xorriso, makeself, perl, pkgconfig, nukeReferences
   , javaBindings ? false, jdk ? null
   , pythonBindings ? false, python ? null
   , enableExtensionPack ? false, requireFile ? null, patchelf ? null, fakeroot ? null
  
positive.code:   buildInputs =
      [ iasl dev86 libxslt libxml2 xproto libX11 libXext libXcursor qt4 libIDL SDL
        libcap glib lvm2 python alsaLib curl libvpx pam xorriso makeself perl
        pkgconfig which libXmu ]
      ++ optional javaBindings jdk
      ++ optional pythonBindings python
      ++ optional pulseSupport pulseaudio;
  
negative.code:       mkdir -p $out/share/icons/hicolor/$size/apps
        ln -s $libexec/icons/$size/*.png $out/share/icons/hicolor/$size/apps
      done
  
      # Get rid of src cruft.
      rm -rf $out/libexec/virtualbox/src
  
      # Get rid of a reference to linux.dev.
      nuke-refs $out/lib/modules/*/misc/*.ko
    '';
  
    passthru = { inherit version; /* for guest additions */ };
  