#エラー内容
LodeError

Unable to autoload constant HomeController, expected /home/vagrant/work/bookers1_debug/app/controllers/home_controller.rb to define it

    else
      require_or_load(expanded, qualified_name)
      raise LoadError, "Unable to autoload constant #{qualified_name}, expected #{file_path} to define it" unless from_mod.const_defined?(const_name, false)
      return from_mod.const_get(const_name)
    end
  elsif mod = autoload_module!(from_mod, const_name, qualified_name, path_suffix)

Rails.root: /home/vagrant/work/bookers1_debug

Application Trace | Framework Trace | Full Trace
activesupport (5.2.4.3) lib/active_support/dependencies.rb:511:in `load_missing_constant'
bootsnap (1.4.6) lib/bootsnap/load_path_cache/core_ext/active_support.rb:61:in `block in load_missing_constant'
bootsnap (1.4.6) lib/bootsnap/load_path_cache/core_ext/active_support.rb:17:in `allow_bootsnap_retry'
bootsnap (1.4.6) lib/bootsnap/load_path_cache/core_ext/active_support.rb:60:in `load_missing_constant'
activesupport (5.2.4.3) lib/active_support/dependencies.rb:195:in `const_missing'
activesupport (5.2.4.3) lib/active_support/inflector/methods.rb:283:in `const_get'
activesupport (5.2.4.3) lib/active_support/inflector/methods.rb:283:in `block in constantize'
activesupport (5.2.4.3) lib/active_support/inflector/methods.rb:281:in `each'
activesupport (5.2.4.3) lib/active_support/inflector/methods.rb:281:in `inject'
activesupport (5.2.4.3) lib/active_support/inflector/methods.rb:281:in `constantize'
activesupport (5.2.4.3) lib/active_support/dependencies.rb:582:in `get'
activesupport (5.2.4.3) lib/active_support/dependencies.rb:613:in `constantize'
actionpack (5.2.4.3) lib/action_dispatch/http/request.rb:88:in `controller_class_for'
actionpack (5.2.4.3) lib/action_dispatch/http/parameters.rb:101:in `binary_params_for?'
actionpack (5.2.4.3) lib/action_dispatch/http/parameters.rb:92:in `set_binary_encoding'
actionpack (5.2.4.3) lib/action_dispatch/http/parameters.rb:69:in `path_parameters='
actionpack (5.2.4.3) lib/action_dispatch/journey/router.rb:50:in `block in serve'
actionpack (5.2.4.3) lib/action_dispatch/journey/router.rb:35:in `each'
actionpack (5.2.4.3) lib/action_dispatch/journey/router.rb:35:in `serve'
actionpack (5.2.4.3) lib/action_dispatch/routing/route_set.rb:840:in `call'
rack (2.2.3) lib/rack/tempfile_reaper.rb:15:in `call'
rack (2.2.3) lib/rack/etag.rb:27:in `call'
rack (2.2.3) lib/rack/conditional_get.rb:27:in `call'
rack (2.2.3) lib/rack/head.rb:12:in `call'
actionpack (5.2.4.3) lib/action_dispatch/http/content_security_policy.rb:18:in `call'
rack (2.2.3) lib/rack/session/abstract/id.rb:266:in `context'
rack (2.2.3) lib/rack/session/abstract/id.rb:260:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/cookies.rb:670:in `call'
activerecord (5.2.4.3) lib/active_record/migration.rb:559:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (5.2.4.3) lib/active_support/callbacks.rb:98:in `run_callbacks'
actionpack (5.2.4.3) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/debug_exceptions.rb:61:in `call'
web-console (3.7.0) lib/web_console/middleware.rb:135:in `call_app'
web-console (3.7.0) lib/web_console/middleware.rb:22:in `block in call'
web-console (3.7.0) lib/web_console/middleware.rb:20:in `catch'
web-console (3.7.0) lib/web_console/middleware.rb:20:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
railties (5.2.4.3) lib/rails/rack/logger.rb:38:in `call_app'
railties (5.2.4.3) lib/rails/rack/logger.rb:26:in `block in call'
activesupport (5.2.4.3) lib/active_support/tagged_logging.rb:71:in `block in tagged'
activesupport (5.2.4.3) lib/active_support/tagged_logging.rb:28:in `tagged'
activesupport (5.2.4.3) lib/active_support/tagged_logging.rb:71:in `tagged'
railties (5.2.4.3) lib/rails/rack/logger.rb:26:in `call'
sprockets-rails (3.2.1) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/request_id.rb:27:in `call'
rack (2.2.3) lib/rack/method_override.rb:24:in `call'
rack (2.2.3) lib/rack/runtime.rb:22:in `call'
activesupport (5.2.4.3) lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (5.2.4.3) lib/action_dispatch/middleware/static.rb:127:in `call'
rack (2.2.3) lib/rack/sendfile.rb:110:in `call'
railties (5.2.4.3) lib/rails/engine.rb:524:in `call'
puma (3.12.6) lib/puma/configuration.rb:227:in `call'
puma (3.12.6) lib/puma/server.rb:706:in `handle_request'
puma (3.12.6) lib/puma/server.rb:476:in `process_client'
puma (3.12.6) lib/puma/server.rb:334:in `block in run'
puma (3.12.6) lib/puma/thread_pool.rb:135:in `block in spawn_thread'

#原因
home_controller.rbのクラス名称がControllerになっていた。
routes.rbではhome#topとしているのにコントローラー名称がだめ。

Controller
=>
HomeController

▼参考
https://okerablog.com/2018-01-03-082902/
https://stackoverrun.com/ja/q/8095183a

#深堀り
どうやらアプリケーションを立ち上げるときにrailsの中のActionDispatchなるミドルウェア(?ミドルウェアがなにかわかってないが)が働いてる。
###どんな働き
routes.rbからcontroller.rbへルーティングを提供したり色々。

だから今回はController側がroutesから橋渡しが上手く行かなかったのかな。
▼参考　#ActionDispatchについて
https://blog.eiel.info/blog/2014/03/30/action-dispatch/