It's hard to figure out the reason from a big project, but step-by-step debug crashes in this code:

//$di = new Phalcon\DI\FactoryDefault();
$viewEngines = array(
".volt" => function($view, $di) {
$volt = new \Phalcon\Mvc\View\Engine\Volt($view, $di);
$volt->setOptions(array(
'compiledPath' => PATH_APPCACHE . 'views/',
'compiledSeparator' => '',
'stat' => false,
'compileAlways' => true
));

    //register functions...
    //register filters...

    return $volt;
}

);

//Volt
$di->set('view', function() use($viewEngines) {
$view = new \Phalcon\Mvc\View();
$view->setViewsDir(PATH_APP_VIEWS);
$view->registerEngines($viewEngines);
return $view;
});

SEGFAULT happen just after "return $volt;" - which create object for DI container and returns it back.