Why php-memcached incompatible with memcached itself

[PutinVladimir]

<?php
// Use direct access to memcached
$memcached = fsockopen ("unix:///var/run/memcached/memcached.sock",-1);

if (!$memcached) {
    echo "$errstr ($errno)\n";
}

$key = 'key';
$flags = 1;
$expire = 1000;
$data = "test";
$length = strlen($data);

if (!fwrite($memcached, "set {$key} {$flags} {$expire} {$length}\r\n{$data}\r\n")) {
        throw new Exception('Memcached write error.');
}

// Now try get key thru php-memcached
$phpmemcached = new Memcached();
$phpmemcached->setOptions([
    \Memcached::OPT_COMPRESSION => false,
    \Memcached::OPT_BINARY_PROTOCOL => true
]);

$phpmemcached->setOption(Memcached::OPT_USER_FLAGS, 1);

$phpmemcached->addServer('/var/run/memcached/memcached.sock', 0);

$value = $phpmemcached->get($key, null, Memcached::GET_EXTENDED);

var_dump($value);

/*
/array(3) {
  'value' =>
  int(0)
  'cas' =>
  int(35)
  'flags' =>
  int(0)

Where is my data???
*/