# Rails app with hanami fails on hanami dependency I didn't (want to) add

**URL:** <https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126>\
**Category:** questions\
**Created:** [February 19, 2025, 9:59pm UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126 "2025-02-19T21:59:27Z")\
**Posts on this page:** 11\
**Page:** 1

<div class="post-metadata">

**Author:** ![stephan](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@stephan](https://discourse.hanakai.org/u/stephan)\
**Post date:** [February 19, 2025, 9:59pm UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/1 "2025-02-19T21:59:27Z")

</div>

After we sorted through a bunch of problems regarding running a (partial) hanami in a Rails app, I worked to incorporate the learnings and fixes into the sample application I am working on.

For those interested, the prior work is in

- [A hanami slice in a Rails app - #9 by stephan](https://discourse.hanakai.org/t/a-hanami-slice-in-a-rails-app/1118/9)
- [Trouble testing the result of an operation - #9 by alassek](https://discourse.hanakai.org/t/trouble-testing-the-result-of-an-operation/1121/9)
- [Rails and hanami-view don't get along - #9 by stephan](https://discourse.hanakai.org/t/rails-and-hanami-view-dont-get-along/1122/9)

I have uploaded an archive of the current state I am working with to [Proton Drive](https://drive.proton.me/urls/4948J8KHH8#QkhtkxvAKI3Q)

After you extract it you can bundle everything with `bundle --local` to get all the same versions of things I am using.

When I then run `bin/rails zeitwerk:check --trace` you can see my problem:

```auto
** Invoke zeitwerk:check (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute zeitwerk:check
Hold on, I am eager loading the application.
bin/rails aborted!
LoadError: cannot load such file -- hanami/assets (LoadError)

```

I am using zeitwerk’s check as a shortcut to eager loading the application. I am not sure why it suddenly wants `hanami/assets`…

And, once I give it assets, it wants db and it wants … I think it eventually forces me to installed all hanami gems

---

<div class="post-metadata">

**Author:** ![timriley](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.hanakai.org/timriley/32/621_2.png) [@timriley](https://discourse.hanakai.org/u/timriley)\
**Post date:** [February 20, 2025, 12:13am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/2 "2025-02-20T00:13:08Z")

</div>

@stephan You’re doing amazing work uncovering bugs for us. Thank you! ❤

I think I know the fix here. Give me 30 minutes.

---

<div class="post-metadata">

**Author:** ![timriley](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.hanakai.org/timriley/32/621_2.png) [@timriley](https://discourse.hanakai.org/u/timriley)\
**Post date:** [February 20, 2025, 12:33am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/3 "2025-02-20T00:33:47Z")

</div>

@stephan Can you please tell me how to disable the gem caching (into `vendor/gems/`) for this codebase? It makes working with a local copy of the hanami gem really hard.

**UPDATE:** Actually, scratch that request. Initially, even after removing `.bundle/config` and removing everything inside `vendor/gems`, newly installed gems seemed to be reappearing there. But after deleting the directory _entirely_ and trying again in a new shell, it seems I’m good.

---

<div class="post-metadata">

**Author:** ![timriley](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.hanakai.org/timriley/32/621_2.png) [@timriley](https://discourse.hanakai.org/u/timriley)\
**Post date:** [February 20, 2025, 1:56am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/4 "2025-02-20T01:56:05Z")

</div>

@stephan I made some headway. This is about excluding files from Zeitwerk autoloading that require gems that may not be installed. But I’ve just got one or two hitches to figure out. Bear with me and I’ll get you a working answer ASAP.

---

<div class="post-metadata">

**Author:** ![stephan](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@stephan](https://discourse.hanakai.org/u/stephan)\
**Post date:** [February 20, 2025, 2:29am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/5 "2025-02-20T02:29:24Z")

</div>

Thank you!

I had previously found [hanami/lib/hanami/extensions.rb at main · hanami/hanami · GitHub](https://github.com/hanami/hanami/blob/main/lib/hanami/extensions.rb) and suspected it had something to do with this. I think it is not, my hunch is that adding more code like this is what’s needed?

Either way! Again, thank you for the help!

---

<div class="post-metadata">

**Author:** ![timriley](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.hanakai.org/timriley/32/621_2.png) [@timriley](https://discourse.hanakai.org/u/timriley)\
**Post date:** [February 20, 2025, 3:19am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/6 "2025-02-20T03:19:59Z")

</div>

Hi again @stephan! OK, try this:

Update your `Gemfile` to depend on these PR branches:

- [Exclude from autoloading any files depending on potentially non-installed gems by timriley · Pull Request #1498 · hanami/hanami · GitHub](https://github.com/hanami/hanami/pull/1498) (I’ve based this one on top of the `fix-error-in-operation-extension-for-no-db-apps` branch of hanami/hanami that you’re already using)
- [Exclude tilt extensions from autoloading by timriley · Pull Request #262 · hanami/view · GitHub](https://github.com/hanami/view/pull/262)

```ruby
gem "hanami", github: "hanami/hanami", branch: "exclude-more-files-from-zeitwerk"
gem "hanami-view", github: "hanami/view", branch: "exclude-more-files-from-zeitwerk"

```

Then, remove everything inside `slices/hanami_predictor/relations/` as well as the `slices/hanami_predictor/db` directories. These depend on the hanami-db gem, which you don’t have bundled.

After that, running `bin/rails zeitwerk:check --trace` should get you an error that is more within your control:

```auto
❯ bin/rails zeitwerk:check --trace
** Invoke zeitwerk:check (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute zeitwerk:check
Hold on, I am eager loading the application.
bin/rails aborted!
NoMethodError: undefined method 'describe' for module RSpec (NoMethodError)

RSpec.describe "Predictor Slice" do
     ^^^^^^^^^
/Users/tim/Source/scratch/sportsball/slices/hanami_predictor/spec/operations/create_prediction_spec.rb:2:in '<main>'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/3.4.0/bundled_gems.rb:82:in 'Kernel.require'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/3.4.0/bundled_gems.rb:82:in 'block (2 levels) in Kernel#replace_require'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/bootsnap-1.18.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in 'Kernel#require'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/core_ext/kernel.rb:26:in 'Kernel#require'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/cref.rb:63:in 'Module#const_get'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/cref.rb:63:in 'Zeitwerk::Cref#get'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:173:in 'block in Zeitwerk::Loader::EagerLoad#actual_eager_load_dir'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/helpers.rb:47:in 'block in Zeitwerk::Loader::Helpers#ls'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/helpers.rb:25:in 'Array#each'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/helpers.rb:25:in 'Zeitwerk::Loader::Helpers#ls'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:168:in 'Zeitwerk::Loader::EagerLoad#actual_eager_load_dir'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:17:in 'block (2 levels) in Zeitwerk::Loader::EagerLoad#eager_load'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:16:in 'Hash#each'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:16:in 'block in Zeitwerk::Loader::EagerLoad#eager_load'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:10:in 'Thread::Mutex#synchronize'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader/eager_load.rb:10:in 'Zeitwerk::Loader::EagerLoad#eager_load'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader.rb:430:in 'block in Zeitwerk::Loader.eager_load_all'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader.rb:428:in 'Array#each'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/zeitwerk-2.7.2/lib/zeitwerk/loader.rb:428:in 'Zeitwerk::Loader.eager_load_all'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/zeitwerk_checker.rb:6:in 'Rails::ZeitwerkChecker.check'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/tasks/zeitwerk.rake:29:in 'block (2 levels) in <main>'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:281:in 'block in Rake::Task#execute'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:281:in 'Array#each'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:281:in 'Rake::Task#execute'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:219:in 'block in Rake::Task#invoke_with_call_chain'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:199:in 'Monitor#synchronize'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:199:in 'Rake::Task#invoke_with_call_chain'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/task.rb:188:in 'Rake::Task#invoke'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:188:in 'Rake::Application#invoke_task'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:138:in 'block (2 levels) in Rake::Application#top_level'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:138:in 'Array#each'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:138:in 'block in Rake::Application#top_level'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:147:in 'Rake::Application#run_with_threads'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:132:in 'Rake::Application#top_level'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/commands/rake/rake_command.rb:27:in 'block (2 levels) in Rails::Command::RakeCommand.perform'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/application.rb:214:in 'Rake::Application#standard_exception_handling'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/commands/rake/rake_command.rb:27:in 'block in Rails::Command::RakeCommand.perform'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/commands/rake/rake_command.rb:44:in 'block in Rails::Command::RakeCommand.with_rake'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/rake-13.2.1/lib/rake/rake_module.rb:59:in 'Rake.with_application'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/commands/rake/rake_command.rb:41:in 'Rails::Command::RakeCommand.with_rake'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/commands/rake/rake_command.rb:20:in 'Rails::Command::RakeCommand.perform'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/command.rb:156:in 'Rails::Command.invoke_rake'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/command.rb:73:in 'block in Rails::Command.invoke'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/command.rb:149:in 'Rails::Command.with_argv'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/command.rb:69:in 'Rails::Command.invoke'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/railties-7.2.2.1/lib/rails/commands.rb:18:in '<main>'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/3.4.0/bundled_gems.rb:82:in 'Kernel.require'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/3.4.0/bundled_gems.rb:82:in 'block (2 levels) in Kernel#replace_require'
/Users/tim/.local/share/mise/installs/ruby/3.4.2/lib/ruby/gems/3.4.0/gems/bootsnap-1.18.4/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in 'Kernel#require'
bin/rails:4:in '<main>'
Tasks: TOP => zeitwerk:check

```

This error arises because it’s trying to load a spec file, because you’ve put the spec files directly inside the slice directory.

To prevent these from being autoloaded, create a `slices/hanami_predictor/config/slice.rb` file with the following:

```ruby
# frozen_string_literal: true

module HanamiPredictor
  class Slice < Hanami::Slice
    autoloader.ignore(File.expand_path(File.join( __dir__ , "..", "spec")))
  end
end

```

After that, running `zeitwerk:check` is all clear!

```auto
❯ bin/rails zeitwerk:check --trace
** Invoke zeitwerk:check (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute zeitwerk:check
Hold on, I am eager loading the application.
All is good!

```

---

<div class="post-metadata">

**Author:** ![stephan](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@stephan](https://discourse.hanakai.org/u/stephan)\
**Post date:** [February 20, 2025, 5:34am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/7 "2025-02-20T05:34:03Z")

</div>

What an amazing and thorough response!! Once again, I can confirm that this works for me also.

Whenever I have gem changes I need to run my source code pipeline from the very beginning and since this is Chapter 10… that will take a minute. I hope to have the generator code and source code pushed up soon and will post back here when I do!

Thank you!

---

<div class="post-metadata">

**Author:** ![stephan](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@stephan](https://discourse.hanakai.org/u/stephan)\
**Post date:** [February 26, 2025, 5:42am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/8 "2025-02-26T05:42:43Z")

</div>

This may mean nothing to you, but it means a great deal to me! This is the successful pipeline run for all the source code the book - all the source code, because that’s it: Getting the hanami code together was the last code addition I wanted to make.

Thank you so much everyone, especially @timriley @cllns!

Oh, and what we have been working on are the boxes in the little red ellipse 🙂 Thanks again!

 ![Screenshot 2025-02-25 at 10.37.20 PM](https://canada1.discourse-cdn.com/flex030/uploads/hanamirb/original/1X/fbba9fc7f653f4038cf07889972ad0e269cdd1de.png)

---

<div class="post-metadata">

**Author:** ![timriley](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.hanakai.org/timriley/32/621_2.png) [@timriley](https://discourse.hanakai.org/u/timriley)\
**Post date:** [February 26, 2025, 5:49am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/9 "2025-02-26T05:49:11Z")

</div>

Amazing! I’m so glad we could help you, @stephan. I’d like to release all the changes we made for you. Realistically, that will have to be next week, I hope that’s ok.

---

<div class="post-metadata">

**Author:** ![stephan](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@stephan](https://discourse.hanakai.org/u/stephan)\
**Post date:** [February 26, 2025, 5:50am UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/10 "2025-02-26T05:50:47Z")

</div>

I can productively and happily continue with what I have. If I have the opportunity to go back later and remove the branches and a hack or two, that will be no bother at all!

---

<div class="post-metadata">

**Author:** ![stephan](https://avatars.discourse-cdn.com/v4/letter/s/8baadc/32.png) [@stephan](https://discourse.hanakai.org/u/stephan)\
**Post date:** [March 1, 2025, 10:31pm UTC](https://discourse.hanakai.org/t/rails-app-with-hanami-fails-on-hanami-dependency-i-didnt-want-to-add/1126/11 "2025-03-01T22:31:03Z")

</div>

For folks interested in the final result. After some hiccups, I was able to get things pushed and you can now find it here:

> **[package-based-rails-applications-book/c9s02/sportsball at main ·...](https://github.com/shageman/package-based-rails-applications-book/tree/main/c9s02/sportsball)**
>
> Contribute to shageman/package-based-rails-applications-book development by creating an account on GitHub.

You’ll find that the repo is all the various stages I am morphing the `Sportsball` sample application through. The linked folder is a Rails app where one piece, namely the prediction of competition results is handled inside of a Hanami slice (it really comes down to one operation: [package-based-rails-applications-book/c9s02/sportsball/slices/hanami\_predictor/operations/create\_prediction.rb at main · shageman/package-based-rails-applications-book · GitHub](https://github.com/shageman/package-based-rails-applications-book/blob/main/c9s02/sportsball/slices/hanami_predictor/operations/create_prediction.rb)).

Thanks for all the help!