Ubuntu18.04 で コマンド$ rails server を実行した時にエラーが出た話

# 目的

- サーバをスタートするコマンド`$ rails server`を実行した時のエラー解決法を知る。
- ほぼほぼすでに投稿してある記事と内容は一緒である。  
[Mac で コマンド$ rails server を実行した時にエラーが出た話](https://qiita.com/miriwo/items/106ab25f55d62b1eb847)

# エラー内容

```terminal
$ rails s
=> Booting Puma
=> Rails 6.0.0 application starting in development 
=> Run `rails server --help` for more startup options
RAILS_ENV=development environment is not defined in config/webpacker.yml, falling back to production environment
Exiting
Traceback (most recent call last):
        68: from bin/rails:4:in `<main>'
        67: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `require'
        66: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:291:in `load_dependency'

・
・
・
2: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:84:in `data'
         1: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:87:in `load'
/home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:91:in `rescue in load': Webpacker configuration file not found /home/miriwo/workspace/aaa/config/webpacker.yml. Please run rails webpacker:install Error: No such file or directory @ rb_sysopen - /home/miriwo/workspace/aaa/config/webpacker.yml (RuntimeError)
```

# 解決方法

- コマンド`$ rails webpacker:install`を実行しようとしたところでエラーがでた。

```terminal
$ rails webpacker:install
Yarn not installed. Please download and install Yarn from https://yarnpkg.com/lang/en/docs/install/
```

- yarnが入っていないためエラーが出たようなのでコマンド`brew install yarn`を実行して入れた。

```terminal
$ brew install yarn
==> Installing dependencies for yarn: node
==> Installing yarn dependency: node
==> Downloading https://homebrew.bintray.com/bottles/node-12.12.0.high_sierra.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/0f/0f35e88be5a84c808dba472d053af25639b300c095392f63e85d9ae94cf12b20
・
・
・
```

- コマンド`$ rails webpacker:install`を実行した。

```terminal
$ rails webpacker:install
RAILS_ENV=development environment is not defined in config/webpacker.yml, falling back to production environment
      create  config/webpacker.yml
Copying webpack core config
      create  config/webpack
      create  config/webpack/development.js
      create  config/webpack/environment.js
・
・
・
```

- コマンド`$ rails server`を実行したところ、正常にローカルサーバが起動した。

```terminal
$ rails s
=> Booting Puma
=> Rails 6.0.0 application starting in development 
=> Run `rails server --help` for more startup options
Puma starting in single mode...
* Version 3.12.1 (ruby 2.6.4-p104), codename: Llamas in Pajamas
* Min threads: 5, max threads: 5
* Environment: development
* Listening on tcp://localhost:3000
・
・
・
```

# 付録

- コマンド`$ rails server`を実行した時のエラーを記載する。

```terminal
$ rails s
=> Booting Puma
=> Rails 6.0.0 application starting in development 
=> Run `rails server --help` for more startup options
RAILS_ENV=development environment is not defined in config/webpacker.yml, falling back to production environment
Exiting
Traceback (most recent call last):
        68: from bin/rails:4:in `<main>'
        67: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `require'
        66: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:291:in `load_dependency'
        65: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `block in require'
        64: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
        63: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
        62: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
        61: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
        60: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
        59: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands.rb:18:in `<main>'
        58: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/command.rb:46:in `invoke'
        57: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/command/base.rb:65:in `perform'
        56: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/thor.rb:387:in `dispatch'
        55: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/thor/invocation.rb:126:in `invoke_command'
        54: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/thor/command.rb:27:in `run'
        53: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:138:in `perform'
        52: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:138:in `tap'
        51: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:147:in `block in perform'
        50: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:37:in `start'
        49: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:77:in `log_to_stdout'
        48: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/server.rb:354:in `wrapped_app'
        47: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/server.rb:219:in `app'
        46: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/server.rb:319:in `build_app_and_options_from_config'
        45: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:40:in `parse_file'
        44: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:49:in `new_from_string'
        43: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:49:in `eval'
        42: from config.ru:in `<main>'
        41: from config.ru:in `new'
        40: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:55:in `initialize'
        39: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:55:in `instance_eval'
        38: from config.ru:3:in `block in <main>'
        37: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:48:in `require_relative'
        36: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `require'
        35: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:291:in `load_dependency'
        34: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `block in require'
        33: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/zeitwerk-2.2.0/lib/zeitwerk/kernel.rb:23:in `require'
        32: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
        31: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
        30: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
        29: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
        28: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
        27: from /home/miriwo/workspace/aaa/config/environment.rb:5:in `<main>'
        26: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/application.rb:363:in `initialize!'
        25: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:60:in `run_initializers'
        24: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:205:in `tsort_each'
        23: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:226:in `tsort_each'
        22: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:347:in `each_strongly_connected_component'
        21: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:347:in `call'
        20: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:347:in `each'
        19: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:349:in `block in each_strongly_connected_component'
        18: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:431:in `each_strongly_connected_component_from'
        17: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
        16: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:228:in `block in tsort_each'
        15: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:61:in `block in run_initializers'
        14: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:32:in `run'
        13: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:32:in `instance_exec'
        12: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/railtie.rb:84:in `block in <class:Engine>'
        11: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker.rb:27:in `bootstrap'
        10: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/commands.rb:14:in `bootstrap'
         9: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/manifest.rb:18:in `refresh'
         8: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/manifest.rb:83:in `load'
         7: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:47:in `public_manifest_path'
         6: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:43:in `public_output_path'
         5: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:39:in `public_path'
         4: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:80:in `fetch'
         3: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:84:in `data'
         2: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:88:in `load'
         1: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:88:in `read'
/home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:88:in `read': No such file or directory @ rb_sysopen - /home/miriwo/workspace/aaa/config/webpacker.yml (Errno::ENOENT)
        67: from bin/rails:4:in `<main>'
        66: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `require'
        65: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:291:in `load_dependency'
        64: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `block in require'
        63: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
        62: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
        61: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
        60: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
        59: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
        58: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands.rb:18:in `<main>'
        57: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/command.rb:46:in `invoke'
        56: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/command/base.rb:65:in `perform'
        55: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/thor.rb:387:in `dispatch'
        54: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/thor/invocation.rb:126:in `invoke_command'
        53: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/thor-0.20.3/lib/thor/command.rb:27:in `run'
        52: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:138:in `perform'
        51: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:138:in `tap'
        50: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:147:in `block in perform'
        49: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:37:in `start'
        48: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/commands/server/server_command.rb:77:in `log_to_stdout'
        47: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/server.rb:354:in `wrapped_app'
        46: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/server.rb:219:in `app'
        45: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/server.rb:319:in `build_app_and_options_from_config'
        44: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:40:in `parse_file'
        43: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:49:in `new_from_string'
        42: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:49:in `eval'
        41: from config.ru:in `<main>'
        40: from config.ru:in `new'
        39: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:55:in `initialize'
        38: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/rack-2.0.7/lib/rack/builder.rb:55:in `instance_eval'
        37: from config.ru:3:in `block in <main>'
        36: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:48:in `require_relative'
        35: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `require'
        34: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:291:in `load_dependency'
        33: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/activesupport-6.0.0/lib/active_support/dependencies.rb:325:in `block in require'
        32: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/zeitwerk-2.2.0/lib/zeitwerk/kernel.rb:23:in `require'
        31: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
        30: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
        29: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
        28: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
        27: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
        26: from /home/miriwo/workspace/aaa/config/environment.rb:5:in `<main>'
        25: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/application.rb:363:in `initialize!'
        24: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:60:in `run_initializers'
        23: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:205:in `tsort_each'
        22: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:226:in `tsort_each'
        21: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:347:in `each_strongly_connected_component'
        20: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:347:in `call'
        19: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:347:in `each'
        18: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:349:in `block in each_strongly_connected_component'
        17: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:431:in `each_strongly_connected_component_from'
        16: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
        15: from /home/linuxbrew/.linuxbrew/Cellar/ruby/2.6.5/lib/ruby/2.6.0/tsort.rb:228:in `block in tsort_each'
        14: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:61:in `block in run_initializers'
        13: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:32:in `run'
        12: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/railties-6.0.0/lib/rails/initializable.rb:32:in `instance_exec'
        11: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/railtie.rb:84:in `block in <class:Engine>'
        10: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker.rb:27:in `bootstrap'
         9: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/commands.rb:14:in `bootstrap'
         8: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/manifest.rb:18:in `refresh'
         7: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/manifest.rb:83:in `load'
         6: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:47:in `public_manifest_path'
         5: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:43:in `public_output_path'
         4: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:39:in `public_path'
         3: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:80:in `fetch'
         2: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:84:in `data'
         1: from /home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:87:in `load'
/home/linuxbrew/.linuxbrew/lib/ruby/gems/2.6.0/gems/webpacker-4.0.7/lib/webpacker/configuration.rb:91:in `rescue in load': Webpacker configuration file not found /home/miriwo/workspace/aaa/config/webpacker.yml. Please run rails webpacker:install Error: No such file or directory @ rb_sysopen - /home/miriwo/workspace/aaa/config/webpacker.yml (RuntimeError)
```