Autoloading helpers fails initially in Rails 7.x, but succeeds on the second attempt

[bradgessler]

Steps to reproduce

When I try loading a Rails Application in Ruby 7.0, the app/helpers autoload path does not appear to be working from my gems engine.

Here's the script to reproduce the issue NOT working under 7.0:

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "sitepress", github: "sitepress/sitepress", branch: "rails-7"
  gem "rails", github: "rails/rails", branch: "main"
end

require "sitepress/server"  # Load all the stuff needed setup the configuration below.

# Setup defaults for stand-alone Sitepress server in the current path. This
# can, and should, be over-ridden by the end-user in the `config/site.rb` file.
Sitepress.configure do |config|
  config.routes = false
  config.site = Sitepress::Site.new root_path: "."
end

# Create the module that should autoload without an issues.
require 'fileutils'
FileUtils.mkdir_p 'helpers'
File.write "helpers/foo_helper.rb", "module FooHelper; end;"

# Boot the Rails app
app = Sitepress::Server
app.initialize!

puts "Loading ::SiteController fails in Rails 7.0"
# See https://github.com/sitepress/sitepress/blob/rails-7/sitepress-rails/lib/sitepress/engine.rb#L15 for helper path configuration
# See https://github.com/sitepress/sitepress/blob/rails-7/sitepress-server/lib/sitepress/server.rb for the configuration of the Rails app this boots
p ::SiteController # This will raise an exception

Now for code that shows this WORKING under Rails 6:

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "sitepress", github: "sitepress/sitepress", branch: "rails-7"
  gem "rails"
end

require "sitepress/server"  # Load all the stuff needed setup the configuration below.

# Setup defaults for stand-alone Sitepress server in the current path. This
# can, and should, be over-ridden by the end-user in the `config/site.rb` file.
Sitepress.configure do |config|
  config.routes = false
  config.site = Sitepress::Site.new root_path: "."
end

# Create the module that should autoload without an issues.
require 'fileutils'
FileUtils.mkdir_p 'helpers'
File.write "helpers/foo_helper.rb", "module FooHelper; end;"

# Boot the Rails app
app = Sitepress::Server
app.initialize!

puts "Loading ::SiteController succeeds in Rails 6.x"
p ::SiteController # This will not raise an exception

Finally, in a third example under Rails 7.0, I demonstrate that this is WORKING when I attempt to load the constant a second time:

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "sitepress", github: "sitepress/sitepress", branch: "rails-7"
  gem "rails", github: "rails/rails", branch: "main"
end

# require "sitepress/boot"
require "sitepress/server"  # Load all the stuff needed setup the configuration below.

# Setup defaults for stand-alone Sitepress server in the current path. This
# can, and should, be over-ridden by the end-user in the `config/site.rb` file.
Sitepress.configure do |config|
  config.routes = false
  config.site = Sitepress::Site.new root_path: "."
end

# Create the module that should autoload without an issues.
require 'fileutils'
FileUtils.mkdir_p 'helpers'
File.write "helpers/foo_helper.rb", "module FooHelper; end;"

# Boot the Rails app
app = Sitepress::Server
app.initialize!

puts "Loading ::SiteController fails in Rails 7.0 on the first attempt"
begin
  p ::SiteController
rescue => e
  puts "Failed with #{e.inspect}"
end

puts "Loading ::SiteController succeeds in Rails 7.0 on the second attempt"
p ::SiteController

The following source files may be helpful to help diagnose the issue:

• https://github.com/sitepress/sitepress/blob/rails-7/sitepress-rails/lib/sitepress/engine.rb#L15 for helper path configuration
• https://github.com/sitepress/sitepress/blob/rails-7/sitepress-server/lib/sitepress/server.rb for the configuration of the Rails app this boots

Expected behavior

I expect the FooHelper to be resolved in Rails 7.x, as it does in Rails 6.x. Here's what a succesful script run looks like from above:

SiteController

Actual behavior

The FooHelper module is not resolved when Rails attempts to find it. Here's what the error looks like from the first Rails 7.x script above:

/Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/activesupport/lib/active_support/inflector/methods.rb:280:in `constantize': uninitialized constant FooHelper (NameError)
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/activesupport/lib/active_support/core_ext/string/inflections.rb:74:in `constantize'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/actionpack/lib/abstract_controller/helpers.rb:177:in `block in modules_for_helpers'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/actionpack/lib/abstract_controller/helpers.rb:170:in `map!'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/actionpack/lib/abstract_controller/helpers.rb:170:in `modules_for_helpers'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/actionpack/lib/action_controller/metal/helpers.rb:104:in `modules_for_helpers'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/actionpack/lib/abstract_controller/helpers.rb:148:in `helper'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/rails-a692e63bf400/actionpack/lib/action_controller/railties/helpers.rb:19:in `inherited'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/sitepress-cd078ab7255c/sitepress-server/rails/app/controllers/application_controller.rb:1:in `<top (required)>'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/zeitwerk-2.5.0.beta3/lib/zeitwerk/kernel.rb:27:in `require'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/zeitwerk-2.5.0.beta3/lib/zeitwerk/kernel.rb:27:in `require'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/bundler/gems/sitepress-cd078ab7255c/sitepress-server/rails/app/controllers/site_controller.rb:1:in `<top (required)>'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/zeitwerk-2.5.0.beta3/lib/zeitwerk/kernel.rb:27:in `require'
	from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/zeitwerk-2.5.0.beta3/lib/zeitwerk/kernel.rb:27:in `require'
	from bug.rb:40:in `<main>'

System configuration

Rails version: 7.x

Ruby version: 3.x

[rafaelfranca]

This could be an issue on sitepress. Are you able to reproduce in a regular Rails application without using Sitepress?

[bradgessler]

Short answer is no, I haven't tried reproducing this in a vanilla Rails 7.x app. I doubt its an issue there since helpers are so heavily tested.

The longer answer is that Sitepress itself is a stripped-down Rails application (see https://github.com/sitepress/sitepress/blob/rails-7/sitepress-server/lib/sitepress/server.rb). The paths that are not loading are set in an engine (see https://github.com/sitepress/sitepress/blob/rails-7/sitepress-rails/lib/sitepress/engine.rb#L21-L26). While its not a full-blown Rails application in a rails new foo_bar sense, it should serve as a simpler use case since it is only loading a subset of Rails.

The reason I think this is of interest is that if I'm seeing this strange behavior in what should be a "simple use case", it will appear in more complicated rails apps and/or gems.

If this turns out to not be a bug in the Rails 7.x autoloading features, I'd guess that whatever I've found is worth documenting in the autoloading change log, autoloading docs, or the Rails engine docs.

[fxn]

I've played around for a few minutes. Some details I see:

First, let's eliminate case (3) from the equation. In Ruby, you know that if you have this

# foo.rb
class Foo
  raise

  def x
  end
end

and then

begin
  require "foo"
rescue
  # ignored
end

Foo

That works, because the Foo constant was actually defined. You are not loading again and succeeding, it was the first load the succeeded partially. Of course, instances of Foo won't respond to #x, that is expected.

That is in essence what is happening in case (3).

There's one difference between case (1) and case (2), if you

pp ActiveSupport::Dependencies.autoload_paths

after initialization, you'll see tmp/helpers is present in (2), and missing in (1).

I don't know why is that yet, just reached this point by now, but looks like the problem is the configurations, for some reason, are different between both versions.

I'll try to dig into it, thanks a lot for testing the alpha ❤️.

[bradgessler]

I tested against alpha2 and dug into some of the docs in there to see if any of the new info in the README (https://github.com/rails/rails/blob/main/guides/source/autoloading_and_reloading_constants.md) would help out.

I discovered Rails.autoloaders.log! and dropped that into the loading. Here's what I get on the first attempt to load ::SiteController

[1] pry(#<Sitepress::CLI>)> pp ActiveSupport::Dependencies.autoload_paths
["/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns"]
=> ["/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns"]
[2] pry(#<Sitepress::CLI>)> ::SiteController
Zeitwerk@rails.main: constant ApplicationHelper loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers/application_helper.rb
NameError: uninitialized constant PageHelper
from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-7.0.0.alpha2/lib/active_support/inflector/methods.rb:280:in `constantize'

Then on the second attempt:

[3] pry(#<Sitepress::CLI>)> pp ActiveSupport::Dependencies.autoload_paths
["/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns"]
=> ["/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers",
 "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns"]
[4] pry(#<Sitepress::CLI>)> ::SiteController
Zeitwerk@rails.main: constant ApplicationController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb
Zeitwerk@rails.main: constant Sitepress::SitePages loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb
Zeitwerk@rails.main: constant SiteController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb
=> SiteController

From what I observe, the ActiveSupport::Dependencies.autoload_paths are the same between both attempts, but the Zeitwork logger is kicking in on the second attempt to reference that controller.

---

@fxn people don't say this enough in OSS projects, but much 🤟and 🤗 for digging into this issue. I'm going to keep working at it too and see if I can understand the problem better.

[bradgessler]

I found another surprising thing: the Rails.autoloaders.main.autoloads paths changes after ::SiteController successfully loads on the second attempt.

[1] pry(#<Sitepress::CLI>)> Rails.autoloaders.main.autoloads
=> #<Zeitwerk::Autoloads:0x00007fef91204f30
 @a2c=
  {"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb"=>[Object, :ApplicationController],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb"=>[Object, :SiteController],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers/application_helper.rb"=>[Object, :ApplicationHelper],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb"=>[Sitepress, :SiteController],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb"=>[Sitepress, :SitePages]},
 @c2a=
  {[Object, :ApplicationController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb",
   [Object, :SiteController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb",
   [Object, :ApplicationHelper]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers/application_helper.rb",
   [Sitepress, :SiteController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb",
   [Sitepress, :SitePages]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb"}>
[2] pry(#<Sitepress::CLI>)> ::SiteController
Zeitwerk@rails.main: constant ApplicationHelper loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers/application_helper.rb
NameError: uninitialized constant PageHelper
from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-7.0.0.alpha2/lib/active_support/inflector/methods.rb:280:in `constantize'

Then I try it again:

[3] pry(#<Sitepress::CLI>)> Rails.autoloaders.main.autoloads
=> #<Zeitwerk::Autoloads:0x00007fef91204f30
 @a2c=
  {"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb"=>[Object, :ApplicationController],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb"=>[Object, :SiteController],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb"=>[Sitepress, :SiteController],
   "/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb"=>[Sitepress, :SitePages]},
 @c2a=
  {[Object, :ApplicationController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb",
   [Object, :SiteController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb",
   [Sitepress, :SiteController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb",
   [Sitepress, :SitePages]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb"}>
[4] pry(#<Sitepress::CLI>)> ::SiteController
Zeitwerk@rails.main: constant ApplicationController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb
Zeitwerk@rails.main: constant Sitepress::SitePages loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb
Zeitwerk@rails.main: constant SiteController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb

Finally when I run Rails.autoloaders.main.autoloads after the controller is successfully loaded, I get a different set of autoload paths:

[5] pry(#<Sitepress::CLI>)> Rails.autoloaders.main.autoloads
=> #<Zeitwerk::Autoloads:0x00007fef91204f30
 @a2c={"/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb"=>[Sitepress, :SiteController]},
 @c2a={[Sitepress, :SiteController]=>"/Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb"}>

I'd expect these paths to not change after the application & Rails boot successfully (assuming no mutations after that)

[fxn]

Regarding the first comment, in the first attempt this tries to load FooHelper, and fails. Because the configuration does not have the directory. In the second attempt, you move on because of the partial evaluation, that code is not executed again, and you are able to move on.

Regarding the second comment. That is internal, private state, and it is mutated in place.

I believe our best hint so far is that the configuration is different. In Rails 6, the directory that contains FooHelper is not in the autoload paths. That is the root of everything (I believe!), FooHelper cannot be autoloaded in the Rails 7 example, and that squares because the configuration does not have it. However, to debug that I'll need to understand your engine, I suspect.

Something that we could do is bisect rails/main.

[bradgessler]

I'm narrowing down the problem to eager loading. First attempt:

[1] pry(#<Sitepress::CLI>)> Rails.autoloaders.main.eager_load
Zeitwerk@rails.main: eager load start
Zeitwerk@rails.main: constant ApplicationHelper loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/helpers/application_helper.rb
NameError: uninitialized constant PageHelper
from /Users/bradgessler/.rbenv/versions/3.0.0/lib/ruby/gems/3.0.0/gems/activesupport-7.0.0.alpha2/lib/active_support/inflector/methods.rb:280:in `constantize'

Second attempt:

[2] pry(#<Sitepress::CLI>)> Rails.autoloaders.main.eager_load
Zeitwerk@rails.main: eager load start
Zeitwerk@rails.main: constant ApplicationController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/application_controller.rb
Zeitwerk@rails.main: constant Sitepress::SitePages loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/concerns/sitepress/site_pages.rb
Zeitwerk@rails.main: constant SiteController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-server/rails/app/controllers/site_controller.rb
Zeitwerk@rails.main: constant Sitepress::SiteController loaded from file /Users/bradgessler/Projects/sitepress/gem/sitepress-rails/rails/app/controllers/sitepress/site_controller.rb
Zeitwerk@rails.main: eager load end
=> nil

Regarding the second comment. That is internal, private state, and it is mutated in place.

I see that now. Thanks for pointing this out.

I believe our best hint so far is that the configuration is different

When you say configuration do you mean my application's configuration or a change to the overall Rails configuration?

[fxn]

When you say configuration do you mean my application's configuration or a change to the overall Rails configuration?

Rails configures Zeitwerk with the contents of ActiveSupport::Dependencies.autoload_paths by the end of application boot, in what we call the finisher.

In your examples, after initialization, ActiveSupport::Dependencies.autoload_paths in Rails 6 contains the directory where FooHelper lives, and in Rails 7, the directory is not there. Hence, FooHelper is not autoloaded (this is consistent with the autoload paths configured). So, what happens after attempting to load FooHelper is not that much important, those are side-effects of partially evaluated code.

What we have to understand is why are the autoload paths different.

[fxn]

# ... original script ...

# Boot the Rails app
app = Sitepress::Server
app.initialize!

pp ActiveSupport::Dependencies.autoload_paths

see what that prints in Rails 7 and Rails 6.

[bradgessler]

I did a git bisect.

$ git bisect good v6.1.4.1
$ git bisect bad v7.0.0.alpha2

Here's what I got as far as "the first bad commit":

2306a8e645627a7913e161b76eeeb7ee6e6724a9 is the first bad commit
commit 2306a8e645627a7913e161b76eeeb7ee6e6724a9
Author: Xavier Noria <fxn@hashref.com>
Date:   Tue Aug 17 05:23:51 2021 +0200

    Setup the once autoloader on bootstrap

 actionpack/test/controller/helper_test.rb          |  4 +-
 actionview/test/actionpack/abstract/helper_test.rb |  8 ++--
 activesupport/lib/active_support/dependencies.rb   |  4 ++
 .../dependencies/zeitwerk_integration.rb           | 50 +-------------------
 railties/lib/rails/application/bootstrap.rb        | 17 +++++++
 railties/lib/rails/application/finisher.rb         | 24 +++++++++-
 railties/lib/rails/engine.rb                       | 29 +++++++-----
 railties/test/application/configuration_test.rb    | 54 ----------------------
 .../test/application/zeitwerk_integration_test.rb  | 48 +++++++++++++++++++
 9 files changed, 116 insertions(+), 122 deletions(-)

Link: 2306a8e

[fxn]

That is awesome, and indeed that commit looks like could be related. It's almost midnight here, I'll continue in another moment, but I believe we have moved forward understanding the issue. Thanks a lot!!!

[bradgessler]

I think I found the problem: 2306a8e#diff-c72ea90e9c6b7c60285006ea4c34548ae9257dffcda0c1b2f41fffd75a14363bR578-R580.

Any rails engine that depends on the before: :set_autoload_paths would break from this change. If I change that to before: :setup_main_autoloader it works.

In my engine when I change:

    # Load paths from `Sitepress#site` into rails so it can render views, helpers, etc. properly.
    initializer :set_sitepress_paths, before: :set_autoload_paths do |app|
      app.paths["app/helpers"].push site.helpers_path.expand_path
      app.paths["app/assets"].push site.assets_path.expand_path
      app.paths["app/views"].push site.root_path.expand_path
      app.paths["app/views"].push site.pages_path.expand_path
    end

to:

    # Load paths from `Sitepress#site` into rails so it can render views, helpers, etc. properly.
    initializer :set_sitepress_paths, before: :setup_main_autoloader do |app|
      app.paths["app/helpers"].push site.helpers_path.expand_path
      app.paths["app/assets"].push site.assets_path.expand_path
      app.paths["app/views"].push site.root_path.expand_path
      app.paths["app/views"].push site.pages_path.expand_path
    end

it works.

[bradgessler]

I know that Rails engines are not that well documented and the API, particularly the callbacks, are brittle. I'm OK with that since Rails engine developers are more technically inclined and can release updates, but I would call this a regression.

I should add that its entirely possible I'm not hooking into the right initializer callback at https://github.com/sitepress/sitepress/blob/rails-7/sitepress-rails/lib/sitepress/engine.rb#L21 in 6.x, but it just happened to work.

Assuming I hooked into the right callback, the ideal fix would be for the 7.x codebase to setup the initializer callback behaviors to fire roughly in the order of 6.x. If that's not possible then I'd propose adding this change to the docs at https://github.com/rails/rails/blob/main/guides/source/autoloading_and_reloading_constants.md.

If updating docs are the way to go, I'm happy to open a PR with those changes.