我正在关注Ruby on rails 4上的Lynda教程。
我遇到了多个问题：
我遇到了安全问题，我不知道如何将其删除
我在创建新内容时不断获得NameError。
我被困住了，任何帮助都会非常感激
mikf$ rails c
/Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/app_rails_loader.rb:39: warning: Insecure world writable dir /usr/local in PATH, mode 040777
/Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/spring-1.3.4/lib/spring/client/run.rb:68: warning: Insecure world writable dir /usr/local in PATH, mode 040777
/Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.4/lib/bundler/shared_helpers.rb:78: warning: Insecure world writable dir /usr/local in PATH, mode 040777
/Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/bundler-1.9.4/lib/bundler/shared_helpers.rb:78: warning: Insecure world writable dir /usr/local in PATH, mode 040777
Loading development environment (Rails 4.2.1)
irb(main):001:0> **subject =Subject.new**
NameError: uninitialized constant Subject
from (irb):1
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/console.rb:110:in `start'
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/console.rb:9:in `start'
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:68:in `console'
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/gems/2.2.0/gems/railties-4.2.1/lib/rails/commands.rb:17:in `<top (required)>'
from /Users/mikf/Documents/simple_cms/bin/rails:8:in `<top (required)>'
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /Users/mikf/.rbenv/versions/2.2.2/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from -e:1:in `<main>'
irb(main):002:0>