FactoryGirl.create issues "LocalJumpError: no block given (yield)" with Rails 5 - factory-bot

Question

I'm in the process of upgrading my app to Rails 5
When running the tests with rails 5 enabled I started to get "LocalJumpError: no block given (yield)" on several object creation sentences like this one:
let!(:entity) { create(:entity) }
This started to happen after I upgraded to Rails 5.0.0
I tried using build instead of create on that line and the error doesn't show up in that case.
Has anyone got a similar issue?
My Entity factory is this one:
FactoryGirl.define do
factory :entity do
entity_type 'A'
account { create(:account) }
ilk []
after(:build) do |entity|
entity.names << build(:name)
entity.addresses << build(:address)
end
trait :incomplete do
incomplete true
end
end
My Gemfile looks like this: https://jpst.it/Lb6N
EDIT
I found out the issue is not with FactoryGirl but with Mongoid gem. I opened a ticket on JIRA for that project. Here's the link but you'll need to have an account with access to Mongoid project at JIRA: https://jira.mongodb.org/browse/MONGOID-4302
The details of this ticket are that by running rspec -b to see the trace, I identified the issue on this line on the mongoid gem:
https://github.com/mongodb/mongoid/blob/master/lib/mongoid/clients/options.rb#L25
The issue disappears if I replace that line (yield self) with just:
self
I'm not sure however if this is a feasible fix, so I opened the ticket mentioned before to get mongoid's feedback and see what can be done.
I'll update again when I get any feedback.

Answer 1

After a lot of debugging I found the source of the issue on a local fork of the mongoid_token gem, which was causing this weird problem. Mongoid and FactoryGirl gems are not related to this issue, neither the original mongoid-token gem.