Enabling Rabbit event_pusher handler causes crash

[rthouvenin]

MongooseIM version: 6.2.1
Installed from: Docker

I would like to enable mod_event_pusher with a RabbitMQ handler, but when I do so MongooseIM crashes on startup with an error message saying that it could not create the RabbitMQ exchanges. I can't see any information on why the exchange creation fails.

Here is the relevant config that I added:

[outgoing_pools.rabbit.event_pusher]
  # I also tried global scope
  scope = "host_type"
  workers = 2

  [outgoing_pools.rabbit.event_pusher.connection]
    host = "<RABBIT_HOST>"
    port = 5672
    username = "<RABBIT_USER>"
    password = "<RABBIT_PASS>"
    confirms_enabled = true

[modules.mod_event_pusher.rabbit.chat_msg_exchange]
  name = "chat"
[modules.mod_event_pusher.rabbit.groupchat_msg_exchange]
  name = "chat"
[modules.mod_event_pusher.rabbit.presence_exchange]
  name = "chat"

(I also tried naming a single exchange and keeping the default for the others)

The connection to RabbitMQ works fine because if I removed the mod_event_pusher section and keep the outgoing pool, I can see in the logs that the connection is successful. The crash occurs only when enabling the event pusher module, while attempting to create the exchanges.

The user has the permissions to create the exchange, as I am able to create them "manually" from the RabbitMQ admin interface. And creating the exchange beforehand does not solve the problem, MongooseIM still tries to create it (or at least crashes with the same error).

Anything I may have missed ?