title: undefined local variable or method `confirmed_at' for #User
body: <p>I am using Rails 3. There is a possible duplicate <a href="https://stackoverflow.com/questions/7857070/rspec-user-test-gives-undefined-local-variable-or-method-confirmed-at">here</a>. But it did not solve my problem, neither did any other solution.</p>
  
  <p>My migration is as follows</p>
  
  <pre><code>class AddConfirmableToDevise &lt; ActiveRecord::Migration
    def change
      change_table(:users) do |t| 
        t.confirmable 
      end
      add_index  :users, :confirmation_token, :unique =&gt; true 
    end
  end
  </code></pre>
  
  <p>I do have <code>devise :confirmable</code> added in <code>User</code> model.</p>
  
  <p>My <code>rake db:migrate</code> gives no output. and my sign up page gives the error:</p>
  
  <pre><code>undefined local variable or method 'confirmed_at' for #User
  </code></pre>
  
  <p>Anybody has a clue?</p>