undefined local variable or method `config' for main:Object (NameError)というエラーに対応したいです。

Question

railsアプリケーションが完成しました。

絵文字の入力に対応するためデフォルトではmtf8だったmysqlをmtf8mb4にしたいと考えました。

その際あるバージョンからのmysqlはデフォルトでmtf8mb4に対応しているとのことだったので、一度mysqlを削除し増田。その後、再インストールしようとしました。

そこでエラーが起こり、なんとかエラーは治り再度mysqlをダウンロードしたものの、rails serverをすると

Traceback (most recent call last):
        37: from bin/rails:3:in `<main>'
        36: from bin/rails:3:in `load'
        35: from /home/ec2-user/environment/tradenote/bin/spring:15:in `<top (required)>'
        34: from /home/ec2-user/environment/tradenote/bin/spring:15:in `require'
        33: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `<top (required)>'
        32: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/lib/spring/binstub.rb:11:in `load'
        31: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/bin/spring:49:in `<top (required)>'
        30: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/lib/spring/client.rb:30:in `run'
        29: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/lib/spring/client/command.rb:7:in `call'
        28: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `call'
        27: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/spring-2.1.0/lib/spring/client/rails.rb:28:in `load'
        26: from /home/ec2-user/environment/tradenote/bin/rails:9:in `<top (required)>'
        25: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/activesupport-5.2.4.1/lib/active_support/dependencies.rb:291:in `require'
        24: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/activesupport-5.2.4.1/lib/active_support/dependencies.rb:257:in `load_dependency'
        23: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/activesupport-5.2.4.1/lib/active_support/dependencies.rb:291:in `block in require'
        22: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
        21: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
        20: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
        19: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
        18: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
        17: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/railties-5.2.4.1/lib/rails/commands.rb:18:in `<top (required)>'
        16: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/railties-5.2.4.1/lib/rails/command.rb:46:in `invoke'
        15: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/railties-5.2.4.1/lib/rails/command/base.rb:69:in `perform'
        14: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/thor-1.0.1/lib/thor.rb:392:in `dispatch'
        13: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/thor-1.0.1/lib/thor/invocation.rb:127:in `invoke_command'
        12: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/thor-1.0.1/lib/thor/command.rb:27:in `run'
        11: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/railties-5.2.4.1/lib/rails/commands/server/server_command.rb:142:in `perform'
        10: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/railties-5.2.4.1/lib/rails/commands/server/server_command.rb:142:in `tap'
         9: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/railties-5.2.4.1/lib/rails/commands/server/server_command.rb:145:in `block in perform'
         8: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/activesupport-5.2.4.1/lib/active_support/dependencies.rb:291:in `require'
         7: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/activesupport-5.2.4.1/lib/active_support/dependencies.rb:257:in `load_dependency'
         6: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/activesupport-5.2.4.1/lib/active_support/dependencies.rb:291:in `block in require'
         5: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:30:in `require'
         4: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require_with_bootsnap_lfi'
         3: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/loaded_features_index.rb:92:in `register'
         2: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `block in require_with_bootsnap_lfi'
         1: from /home/ec2-user/.rvm/gems/ruby-2.5.1/gems/bootsnap-1.4.5/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:22:in `require'
/home/ec2-user/environment/tradenote/config/application.rb:8:in `<top (required)>': undefined local variable or method `config' for main:Object (NameError)

というエラーになって困っています。

１どう対応すれば良いでしょうか？

２また、githubとherokuを使って公開しようと思っているのですが、その際やはりmysql側では消えてしまったデータは必要なのでしょうか？（cloud9側のマイグレーションファイルなどは残っています。）

herokuではprogateSQLを使うらしいのですが…

ご対応の方どうかよろしくお願いいたします。

Comments

[winterboum]

エラーメッセージはその１行だけでなく全体を載せてください

[ganbarou_nippon]

追記しました。