<?php
$di->set('registry', function(){
  return new Phalcon\Registry();
 }, true);
 $this->registry->user = [];
 $this->registry->user['asd'] = 'asd';
 var_dump($this->registry->user['asd']);die;
nothing returned
<?php
$di->set('registry', function(){
  return new Phalcon\Registry();
 }, true);
 $this->registry->user = [];
 $this->registry->user['asd'] = 'asd';
 var_dump($this->registry->user['asd']);die;
nothing returned