anchor.diff:  
       buildInputs = [
         makeWrapper libxml2 gnutls
  -      pkgconfig cmake gnumake yasm python
  +      pkgconfig cmake gnumake yasm python2
         boost libmicrohttpd autoreconfHook
         gettext pcre-cpp yajl fribidi libva
         openssl gperf tinyxml2 taglib libssh swig jre
  
positive.code: { stdenv, lib, fetchurl, makeWrapper
  , pkgconfig, cmake, gnumake, yasm, python
  , boost, avahi, libdvdcss, lame, autoreconfHook
  , gettext, pcre-cpp, yajl, fribidi, which
  , openssl, gperf, tinyxml2, taglib, libssh, swig, jre
  
negative.code:     postInstall = ''
        for p in $(ls $out/bin/) ; do
          wrapProgram $out/bin/$p \
            --prefix PATH ":" "${python2}/bin" \
            --prefix PATH ":" "${glxinfo}/bin" \
            --prefix PATH ":" "${xdpyinfo}/bin" \
            --prefix LD_LIBRARY_PATH ":" "${lib.makeLibraryPath
  