rails g なんちゃら
で叩いた際にエラーが出たり、
帰ってこなかった場合の対処法。
とりあえず、こんなエラー ↓ が出た場合、もしくはいつまでも帰ってこない場合、
/Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/watcher/abstract.rb:30:in `initialize': no implicit conversion of nil into String (TypeError) from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/watcher/abstract.rb:30:in `new' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/watcher/abstract.rb:30:in `block in add' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/watcher/abstract.rb:29:in `map' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/watcher/abstract.rb:29:in `add' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/watcher/polling.rb:20:in `add' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:102:in `rescue in preload' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:115:in `preload' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:143:in `serve' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:131:in `block in run' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:125:in `loop' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application.rb:125:in `run' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/gems/2.3.0/gems/spring-1.6.4/lib/spring/application/boot.rb:18:in `<top (required)>' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' from /Users/natsuneko/.rbenv/versions/2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require' from -e:1:in `<main>'
だいたいどっかに文法ミスがあるので、直せば叩けます。