do not stop daemon when on_join failed

src/risotto/register.py

@@ -7,6 +7,7 @@ from typing import Callable, Optional, List
 from asyncpg import create_pool
 from json import dumps, loads
 from pkg_resources import iter_entry_points
+from traceback import print_exc
 import risotto
 from .utils import _
 from .error import RegistrationError
@@ -319,7 +320,13 @@ class RegisterDispatcher:
                     await log.info_msg(risotto_context,
                                        None,
                                        info_msg)
-                    await module.on_join(risotto_context)
+                    try:
+                        await module.on_join(risotto_context)
+                    except Exception as err:
+                        if get_config()['global']['debug']:
+                            print_exc()
+                        msg = _(f'on_join returns an error in module {submodule_name}: {err}')
+                        await log.error_msg(risotto_context, {}, msg)
 
     async def load(self):
         # valid function's arguments