title: Rspec error: Diff is not a module
body: <p>Following Ryan Bates railscast brand new to rspec.</p>
  
  <p>I get</p>
  
  <pre>
  Guard is now watching at '/Users/thealey/Source/rpd31'
  Guard::RSpec is running, with RSpec 2!
  Running all specs
  /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/diff-lcs-1.1.3/lib/diff/lcs.rb:3:in `': Diff is not a module (TypeError)
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `block in require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:227:in `load_dependency'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-expectations-2.6.0/lib/rspec/expectations/differ.rb:1:in `'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `block in require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:227:in `load_dependency'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-expectations-2.6.0/lib/rspec/expectations.rb:9:in `'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `block in require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:227:in `load_dependency'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/expecting/with_rspec.rb:1:in `'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `block in require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:227:in `load_dependency'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/activesupport-3.0.10/lib/active_support/dependencies.rb:239:in `require'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:207:in `block in expect_with'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:202:in `each'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:202:in `expect_with'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:184:in `expectation_frameworks'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:413:in `configure_expectation_framework'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:165:in `ensure_example_groups_are_configured'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:178:in `set_it_up'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:141:in `subclass'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/example_group.rb:129:in `describe'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/dsl.rb:5:in `describe'
      from /Users/thealey/Source/rpd31/spec/requests/create_projects_spec.rb:3:in `'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:419:in `load'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:419:in `block in load_spec_files'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:419:in `map'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/configuration.rb:419:in `load_spec_files'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/command_line.rb:18:in `run'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/runner.rb:80:in `run_in_process'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/runner.rb:69:in `run'
      from /Users/thealey/.rvm/gems/ruby-1.9.2-p290@rails31/gems/rspec-core-2.6.4/lib/rspec/core/runner.rb:11:in `block in autorun'
  </pre>
  
  <p>Gemfile is    </p>
  
  <pre><code>source 'http://rubygems.org'
  
  gem 'rails', '3.0.10'
  
  
  gem 'mysql2', '0.2.7'
  
  
  gem "authlogic"
  gem 'activesupport', '3.0.10'
  gem 'cancan'
  gem 'will_paginate', "~&gt; 3.0"
  gem 'calendar_date_select', :git =&gt; 'http://github.com/paneq/calendar_date_select.git', :branch =&gt; 'rails3test'
  gem 'bluecloth'
  gem 'rdiscount'
  gem 'capybara'
  gem 'paperclip'
  gem 'mail'
  </code></pre>
  
  <p>any ideas about how to troubleshoot this appreciated.</p>
  
  <p>Edit: I removed commented out lines from Gemfile.</p>
  
  <p>I put diff into my gemfile no change.</p>
  
  <p>This is the output of bundle.</p>
  
  <pre>
  Using rake (0.9.2)
  Using abstract (1.0.0)
  Using activesupport (3.0.10)
  Using builder (2.1.2)
  Using i18n (0.5.0)
  Using activemodel (3.0.10)
  Using erubis (2.6.6)
  Using rack (1.2.3)
  Using rack-mount (0.6.14)
  Using rack-test (0.5.7)
  Using tzinfo (0.3.29)
  Using actionpack (3.0.10)
  Using mime-types (1.16)
  Using polyglot (0.3.2)
  Using treetop (1.4.10)
  Using mail (2.2.19)
  Using actionmailer (3.0.10)
  Using arel (2.0.10)
  Using activerecord (3.0.10)
  Using activeresource (3.0.10)
  Using addressable (2.2.6)
  Using archive-tar-minitar (0.5.2)
  Using authlogic (3.0.3)
  Using crack (0.1.8)
  Using httparty (0.7.8)
  Using multipart-post (1.1.3)
  Using faraday (0.7.4)
  Using multi_json (1.0.3)
  Using oauth2 (0.5.0)
  Using bitly (0.6.1)
  Using bluecloth (2.1.0)
  Using bson (1.3.1)
  Using bson_ext (1.3.1)
  Using bundler (1.0.18)
  Using calendar_date_select (1.16.1) from http://github.com/paneq/calendar_date_select.git (at rails3test)
  Using cancan (1.6.5)
  Using nokogiri (1.5.0)
  Using ffi (1.0.9)
  Using childprocess (0.2.2)
  Using json_pure (1.6.0)
  Using rubyzip (0.9.4)
  Using selenium-webdriver (2.5.0)
  Using xpath (0.1.4)
  Using capybara (1.1.1)
  Using chronic (0.6.4)
  Using cocaine (0.2.0)
  Using colored (1.2)
  Using columnize (0.3.4)
  Using daemons (1.1.4)
  Using diff (0.3.6)
  Using diff-lcs (1.1.3)
  Using eventmachine (0.12.10)
  Using factory_girl (2.1.0)
  Using rdoc (3.9.4)
  Using thor (0.14.6)
  Using railties (3.0.10)
  Using factory_girl_rails (1.2.0)
  Using git_remote_branch (0.3.0)
  Using googlecharts (1.6.7)
  Using gravtastic (3.2.6)
  Using guard (0.6.3)
  Using guard-rspec (0.4.5)
  Using htmldiff (0.0.1)
  Using ruby_core_source (0.1.5)
  Using linecache19 (0.5.12)
  Using mysql2 (0.2.7)
  Using net-ldap (0.2.2)
  Using net-ping (1.5.0)
  Using paperclip (2.4.1)
  Using rails (3.0.10)
  Using rdiscount (1.6.8)
  Using ri_cal (0.8.8)
  Using riddle (1.4.0)
  Using rspec-core (2.6.4)
  Using rspec-expectations (2.6.0)
  Using rspec-mocks (2.6.0)
  Using rspec (2.6.0)
  Using rspec-rails (2.6.1)
  Using ruby-debug-base19 (0.11.25)
  Using ruby-debug19 (0.11.6)
  Using seed_dump (0.3.4)
  Using thin (1.2.11)
  Using thinking-sphinx (2.0.1)
  Using time_diff (0.2.1)
  Using will_paginate (3.0.pre)
  Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.
  </pre>