krenair@tin:~$ php -a
Interactive shell

php > var_dump( Memcached::HAVE_IGBINARY );
int(1)

krenair@mw1059:~$ php -a
Welcome to HipHop Debugger!
Type "help" or "?" for a complete list of commands.

Note: no server specified, debugging local scripts only.
If you want to connect to a server, launch with "-h" or use:
  [m]achine [c]onnect <servername>

hphpd> var_dump( Memcached::HAVE_IGBINARY );
var_dump( Memcached::HAVE_IGBINARY );
bool(false)

$ tail -250000 /a/mw-log/hhvm.log|grep 'igbinary'
Feb 17 14:14:18 mw1161:  #012Warning: could not unserialize value, no igbinary support
Feb 17 14:54:01 mw1088:  #012Warning: could not unserialize value, no igbinary support
Feb 17 15:45:28 mw1247:  #012Warning: could not unserialize value, no igbinary support
Feb 17 16:11:23 mw1238:  #012Warning: could not unserialize value, no igbinary support
Feb 17 16:38:58 mw1032:  #012Warning: could not unserialize value, no igbinary support
Feb 17 17:05:10 mw1239:  #012Warning: could not unserialize value, no igbinary support
Feb 17 17:37:39 mw1018:  #012Warning: could not unserialize value, no igbinary support

		set_error_handler( function ( $errno, $errstr, $errfile, $errline, $errcontext ) {
			wfOneOfTheLoggingFunctions( "memc->get($key) caused warning in Memcached::get: $errstr" );
		}, E_WARNING );
		$result = $this->client->get( $this->encodeKey( $key ), null, $casToken );
		restore_error_handler();