What does `lib` mean in the config.gem call in environment.rb

I see a command in environment.rb that says

config.gem 'thoughtbot-paperclip', :lib => 'paperclip', :source => 'http://gems.github.com'

If I wanted to manually do it, it would be

gem install thoughtbot-papperclip --source http://gems.github.com

Where does the lib 开发者_开发知识库fit in to the command line gem call?

You want to use :lib in your environment.rb if the library name is different with the gem name.

Paperclip doesn't need a library call.

gem.config 'paperclip' 

that should take care of paperclip.

Some gems have crazy dependencies like syntax highlighting and they need to reference a library to meet the dependencies.