Ruby on Rails 3 : “superclass mismatch for class …”

Question

Platform: Mac OSX 10.6

In my terminal, i start the Ruby console with \"rails c\"

While following the Ruby on Rails 3 tutorial to build a class:

Answer 1

This can also happen as such:

# /models/document/geocoder.rb
class Document
  module Geocoder
  end
end

# /models/document.rb
require 'document/geocoder'

class Document < ActiveRecord::Base
  include Geocoder
end

The require loads Document (which has a superclass of Object) before Document < ActiveRecord::Base (which has a different superclass).

I should note that in a Rails environment the require is not usually needed since it has auto class loading.