Debug mode not working in Django environment

[tangochin]

I try to use Tornado with sockjs-tornado in Django environment. In my project Tornado work as Websocket server together with Django in classic Django application.

From client I send session cookie to server and in Tornado get Django user:

from sockjs.tornado import SockJSConnection
from django.utils.importlib import import_module
from django.contrib.auth import get_user
from django.conf import settings

session_engine = import_module(settings.SESSION_ENGINE)

class ChatConnection(SockJSConnection):
    def get_session(self, session_key):
        return session_engine.SessionStore(session_key)

    def get_user(self, session):
        class Dummy(object):
            pass
        django_request = Dummy()
        django_request.session = session

        return get_user(django_request)

    def auth(self, session_id):
        self.django_session = self.get_session(session_id)
        self.user = self.get_user(self.django_session)

    def on_message(self, msg):
        msg = json.loads(msg)

        if msg['event'] == 'auth':
            self.auth(msg['content'])

For run Tornado app in Django environment I use simple management command:

class Command(NoArgsCommand):
    args = ''
    help = 'Run tornado.'

    def handle_noargs(self, **options):
        app = Application(AppRouter.urls, **app_settings)

        app.listen(8880)
        tornado.ioloop.IOLoop.instance().start()

The problem is that in Django environment errors not raised, and Tornado just close connection instead of raise exception. For example, if I write assert False in on_message method, that it will not have any effect other than closed connection. In the app settings debug mode enabled:

app_settings = {
    'debug': True,
}

Out of Django environment all work fine and I see in the shell excited exception.

Django 1.6.8
Tornado 4.0.2
sockjs-tornado 1.0.1