Weird error reporting in ReactPHP

composer.json

{
    "require": {
        "react/event-loop": "0.4.*"
    }
}

loop.php

<?php

require 'vendor/autoload.php';

$loop = React\EventLoop\Factory::create();

var_dump(ini_get('error_reporting'));     // 32767

$loop->addTimer(0, function () {
    var_dump(ini_get('error_reporting')); // 0
    die;
});

$loop->run();