rails: Upgrading Rails to v6-beta3 causes uninitialized constant ActionText::Engine::ApplicationController (NameError)

Steps to reproduce

create app rails v6-beta1
upgrade to rails v6-beta3
run rails s
open localhost:3000

Expected behavior

Open homepage

Actual behavior

Puma caught this error: uninitialized constant ActionText::Engine::ApplicationController (NameError)
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/actiontext-6.0.0.beta3/lib/action_text/engine.rb:39:in `block (2 levels) in <class:Engine>'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:429:in `instance_exec'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:429:in `block in make_lambda'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:201:in `block (2 levels) in halting'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:607:in `block (2 levels) in default_terminator'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:606:in `catch'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:606:in `block in default_terminator'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:202:in `block in halting'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:514:in `block in invoke_before'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:514:in `each'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:514:in `invoke_before'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/callbacks.rb:134:in `run_callbacks'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/execution_wrapper.rb:119:in `complete!'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/execution_wrapper.rb:76:in `ensure in block in run!'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/execution_wrapper.rb:76:in `block in run!'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/execution_wrapper.rb:70:in `tap'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0.beta3/lib/active_support/execution_wrapper.rb:70:in `run!'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/actionpack-6.0.0.beta3/lib/action_dispatch/middleware/executor.rb:12:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/actionpack-6.0.0.beta3/lib/action_dispatch/middleware/static.rb:126:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/rack-2.0.6/lib/rack/sendfile.rb:111:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/actionpack-6.0.0.beta3/lib/action_dispatch/middleware/host_authorization.rb:83:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/sentry-raven-2.9.0/lib/raven/integrations/rack.rb:51:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/webpacker-4.0.0.rc.7/lib/webpacker/dev_server_proxy.rb:29:in `perform_request'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/rack-proxy-0.6.5/lib/rack/proxy.rb:57:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/railties-6.0.0.beta3/lib/rails/engine.rb:523:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/puma-3.12.0/lib/puma/configuration.rb:225:in `call'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/puma-3.12.0/lib/puma/server.rb:658:in `handle_request'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/puma-3.12.0/lib/puma/server.rb:472:in `process_client'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/puma-3.12.0/lib/puma/server.rb:332:in `block in run'
/Users/prokop/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/puma-3.12.0/lib/puma/thread_pool.rb:133:in `block in spawn_thread'

System configuration

Rails version: 6.0.0-beta3

Ruby version: 2.6.0

Using puma: 3.12.0

It seems like an error of puma, but because of uninitialized constant ActionText::Engine::ApplicationController (NameError) I guess it could be bug of rails.

About this issue

Original URL
State: closed
Created 5 years ago
Reactions: 13
Comments: 21 (12 by maintainers)

Commits related to this issue

Bump the dummy app to Rails 6.0.0 Upgrading causes a number of NameErrors: ``` NameError: uninitialized constant ActionText::Engine::ApplicationController ``` The cause of this seems to be missing ... — committed to tijmenb/mail-notify by tijmenb 5 years ago
Bump the dummy app to Rails 6.0.0 Upgrading causes a number of NameErrors: ``` NameError: uninitialized constant ActionText::Engine::ApplicationController ``` The cause of this seems to be missing ... — committed to tijmenb/mail-notify by tijmenb 5 years ago
Upgrade bootsnap to 1.4.5 Was causing some errors in Rails 6 when manually testing. More info: https://github.com/rails/rails/issues/35749 — committed to fosterful/scheduler by joelmichael 5 years ago
Add `ApplicationController` to dummy application Because Action Text expects `ApplicationController` exists. Ref: https://github.com/rails/rails/issues/35749#issuecomment-525083643 — committed to y-yagi/draper by y-yagi 4 years ago
Add `ApplicationController` to dummy application Because Action Text expects `ApplicationController` exists. Ref: https://github.com/rails/rails/issues/35749#issuecomment-525083643 — committed to y-yagi/draper by y-yagi 4 years ago
Add support for Rails 6.0 to `ViewContext::BuildStrategy` (#866) * Add support for Rails 6.0 to `ViewContext::BuildStrategy` In Rails 6.0 the API for `ActionView::Base.new` is changing. `ActionVi... — committed to drapergem/draper by y-yagi 4 years ago

Most upvoted comments

Thanks, @fxn. I gave it a try, but using master did not solve the issue. What did solve it though, was upgrading bootsnap. Only using master did not upgrade it to the lastest version. A new rails app gets bootsnap 1.4.2 while an app upgraded from beta2 to beta3 still has bootsnap 1.4.1. Upgrading bootsnap to 1.4.2 solves the issue.

corneverbruggen on Apr 2, 2019

Ran into the same issue with a minimal Rails test application and fixed it, as suggested above, by adding:

class ApplicationController < ActionController::Base
end

and then inheriting from ApplicationController instead of ActionController::Base. This is a regression in Rails 6.0.0, it wasn’t required to have ApplicationController defined in Rails 5. So I am also wondering if we need this new requirement.

prettycoder on Aug 27, 2019

By following Chapter 2 of the book Component-Based Rails Applications, I stumbled upon the same exception. Adding an ApplicationController indeed helps but prevents from having an application built with components / engines an no app folder in the parent application as suggested by Stephan Hagemann in his book.

Why Would You Delete the app Folder? It is optional to delete the app folder at this point. I am suggesting it for a couple of reasons. For one, it sends a clear message to everyone working on the codebase that something special is going on here. Also, the app folder is not currently needed and is likely not going to be needed in the future. Thus, it would be cruft to keep it around right now. And it can always be added back later if needed.

Hagemann, Stephan. Component-Based Rails Applications (Addison-Wesley Professional Ruby Series) (p. 19). Pearson Education. Kindle Edition.

isc on May 4, 2019

@fxn adding ApplicationController helped. Thanks

bonekost on Apr 17, 2019

Does your application define ApplicationController? Don’t see an autoload for it in the traces.

fxn on Apr 16, 2019

Zeitwerk does not even get a chance to log something?

fxn on Apr 16, 2019

Sorry the reproduction steps are a bit ambiguous because you need to “upgrade”.

Can you reproduce generating a minimal brand new beta 3 application?

fxn on Mar 25, 2019