Getting AbstractController::ActionNotFound instead of NameError when controller module is not defined

[ivandenysov]

Steps to reproduce

1. define a simple controller that includes missing module

# app/controllers/showcase_include_bug_controller.rb
class ShowcaseIncludeBugController < ApplicationController
  include MadeUpModuleName

  def index
  end
end

# config/routes.rb
# ...
get "showcase_include_bug", to: "showcase_include_bug#index"
# ...

2. launch rails server and go to http://localhost:3000/showcase_include_bug

Expected behavior

Rails should raise NameError (uninitialized constant MadeUpModuleName)

Actual behavior

Rails raises AbstractController::ActionNotFound (The action 'index' could not be found for ShowcaseIncludeBugController) or uses ancestor's implementation of index action (if present).

System configuration

Rails version: 6.0.2.1
Ruby version: 2.6.5

[rafaelfranca]

Have you tried with the 6-0-stable branch or the master branch? I believe this problem was already fixed in #37834.