Update from mongoid 6.4.0 to 8.1: has_many broken?

[DcsMarionDickten]

I'll just post the broken code. It worked in Rails 5.2 with Mongoid 6.4 but doesn't in Rails 6.2 with Mongoid 8.1.

module Answers

  class Participant
    include Mongoid::Document
    include Mongoid::Timestamps
    include Mongoid::Attributes::Dynamic

    # ... field definitions

    has_many :participations, class_name: '::Answers::Participation'

    after_destroy :destroy_participations

   # more code

Participations snippet:

module Answers

  class Participation
    include Mongoid::Document
    include Mongoid::Timestamps
    include Mongoid::Attributes::Dynamic

    belongs_to :participant, class_name: '::Answers::Participant'
    # ... more fields, then more code

The has_many has broken when upgrading to Mongoid 7.4 and is still broken in 8.1. I can still get the participations by asking

def participations
     Answers::Participation.where(participant_id: self.id)
end

so it's not too bad although I would like to fix it properly.
Can anybody point me to what is wrong?

[johnnyshields]

@DcsMarionDickten what error are you seeing? Maybe try removing the leading :: in the class name?

[DcsMarionDickten]

There isn't any error. The return value is always an empty array.

I tried without the leading ::, no change. (As a matter of fact, at the beginning it was Answers::Participant and I added the leading double colons in an attempt to see whether it changed anything.)

It does seem to have something to do with the fancy scoping because the rest of my app works perfectly.

The classes Answers::Participant and Answers::Participation are included in a folder that lives inside vendor: vendor/my_gem/models/answers/participant.rb or vendor/my_gem/models/answers/participation.rb, just in case this helps.