title: rails3 rspec issue
body: <p>I am trying out rails3. I am using <a href="http://railstutorial.org/" rel="nofollow noreferrer"><strong>railstutorial</strong></a>
  site to explore more about rails3; the tutorial is very good to begin with (I have minimal experience with rails2).</p>
  
  <p>I have an issue with rspec which is currently blocking my progress. I saw that the tutorial recommended using rspec2.0.0.beta.18 gem; I instead installed rspec2.0.0.beta.20 gem using</p>
  
  <pre><code>bundle install
  </code></pre>
  
  <p>However I find issues with this version of rspec
  My rspec for integration_test looks like:</p>
  
  <pre><code>describe "LayoutLinks" do
    it "should have a About page at '/about'" do  
      get '/about'
      response.should have_selector('h1', :content =&gt; "About Us")
    end 
  end
  </code></pre>
  
  <p>The failure looks like:</p>
  
  <pre><code>Failures:
    1) LayoutLinks should have a About page at '/about'
       Failure/Error: Unable to find matching line from backtrace
       stack level too deep
       # /home/arun/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/forwardable.rb:185
  </code></pre>
  
  <p>(NOTE: Those who have looked at <a href="http://railstutorial.org/chapters/filling-in-the-layout#top" rel="nofollow noreferrer"><strong>Chapter 5</strong></a> will not have issues understanding the context.)</p>
  
  <p>If I change rspec version to 2.0.0.beta.18 in the Gemfile and run rspec I get the following error</p>
  
  <pre><code>arun@ubuntu-world:~/Project/Rails/rails3/sample_app$ rspec spec/
  /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.0/lib/bundler/runtime.rb:27:in `block in setup': You have already activated rspec-core 2.0.0.beta.20, but your Gemfile requires rspec-core 2.0.0.beta.18. Consider using bundle exec. (Gem::LoadError)
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `block in each'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `each'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.0/lib/bundler/spec_set.rb:12:in `each'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.0/lib/bundler/runtime.rb:17:in `setup'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.0/lib/bundler.rb:100:in `setup'
          from /home/arun/Project/Rails/rails3/sample_app/config/boot.rb:8:in `&lt;top (required)&gt;'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from /home/arun/Project/Rails/rails3/sample_app/config/application.rb:1:in `&lt;top (required)&gt;'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from /home/arun/Project/Rails/rails3/sample_app/config/environment.rb:2:in `&lt;top (required)&gt;'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from /home/arun/Project/Rails/rails3/sample_app/spec/spec_helper.rb:3:in `&lt;top (required)&gt;'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from &lt;internal:lib/rubygems/custom_require&gt;:29:in `require'
          from /home/arun/Project/Rails/rails3/sample_app/spec/requests/layout_links_spec.rb:1:in `&lt;top (required)&gt;'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/configuration.rb:302:in `load'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/configuration.rb:302:in `block in load_spec_files'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/configuration.rb:302:in `map'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/configuration.rb:302:in `load_spec_files'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/command_line.rb:18:in `run'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/runner.rb:46:in `run_in_process'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/runner.rb:37:in `run'
          from /home/arun/.rvm/gems/ruby-1.9.2-p0/gems/rspec-core-2.0.0.beta.20/lib/rspec/core/runner.rb:10:in `block in autorun'
  </code></pre>