We upgraded ruby to 3.4.x and rails to 8.x.x and found this new error in our specs:

Upon further looking at it, what was causing it was some internal calls to warden and devise. This command would fail in byebug, or in rspec:

controller.current_user

But re-logging in would fix it, so one of the proposed solutions was this in a `before` action:

    before do
      setup_users :sign_in_role => Role::ROLE_ADMIN
      controller.current_user rescue setup_users({ :sign_in_role => Role::ROLE_ADMIN }) ## adding this line fixed it
    end

Looking at this github comment thread, we see a different proposed solution/workaround:

RSpec.configure do |config|
  config.before(:suite) do
      Rails.application.try(:reload_routes_unless_loaded)
  end
end

And that's the solution we went with, since it's the cleaner of the two.

.^.