title: Rake db:migrate has conflicting test-unit gem dependencies (1.2.3 required, 2.3.0 installed)
body: <p>I'm trying to run</p>
  
  <pre><code>rake db:migrate
  </code></pre>
  
  <p>However each time I do I get the following errors:</p>
  
  <pre><code>rake aborted!
  can't activate test-unit (= 1.2.3), already activated test-unit-2.3.0. Make sure all dependencies are added to Gemfile.
  /Users/petenixey/project/Rakefile:12:in `&lt;top (required)&gt;'
  (See full trace by running task with --trace)
  Peters-MacBook-Air:pingpanel petenixey$ 
  </code></pre>
  
  <p>I have other gems that have dependencies on test-unti 2.3.0 and I can't seem to find anyone else with the same issue. </p>
  
  <p>I've been having a bit of a rubbish time with gem issues recently, would be very grateful for any advice people have. Thank you</p>
  
  <p><strong>Edit</strong> 
  The other thing I've noticed is that if I create a completely fresh Rails project using the gemfiles and gemsets below, rake db:migrate <em>does</em> work. This would suggest to me that something is wrong in an environment setting or similar but I can't figure out what.</p>
  
  <p>---------------- full errors from running with --trace</p>
  
  <pre><code>rake aborted!
  can't activate test-unit (= 1.2.3), already activated test-unit-2.3.0. Make sure all dependencies are added to Gemfile.
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@global/gems/bundler-1.0.13/lib/bundler/rubygems_integration.rb:150:in `block in replace_gem'
  /Users/petenixey/project/tasks/rspec.rake:1:in `&lt;top (required)&gt;'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in `load'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in `block in load'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in `block in load_dependency'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:596:in `new_constants_in'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in `load_dependency'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in `load'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/railties-3.0.7/lib/rails/engine.rb:131:in `block in load_tasks'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/railties-3.0.7/lib/rails/engine.rb:131:in `each'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/railties-3.0.7/lib/rails/engine.rb:131:in `load_tasks'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/railties-3.0.7/lib/rails/application.rb:141:in `load_tasks'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/railties-3.0.7/lib/rails/application.rb:77:in `method_missing'
  /Users/petenixey/Dropbox/rails/pingpanel/Rakefile:12:in `&lt;top (required)&gt;'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2383:in `load'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2383:in `raw_load_rakefile'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2017:in `block in load_rakefile'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2016:in `load_rakefile'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2000:in `block in run'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/gems/rake-0.8.7/bin/rake:31:in `&lt;top (required)&gt;'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/bin/rake:19:in `load'
  /Users/petenixey/.rvm/gems/ruby-1.9.2-p180@test/bin/rake:19:in `&lt;main&gt;'
  </code></pre>
  
  <p>-------------- Gemfile</p>
  
  <pre><code>source :rubygems
  
  gem "authlogic"
  gem "sqlite3-ruby", :require =&gt; "sqlite3"
  gem 'jquery-rails', '&gt;= 0.2.6'
  gem "hoptoad_notifier"
  gem "rake"
  gem "rails", "&gt;=3.0.7"
  gem "heroku"
  
  group :development, :test do
    # up to date
    gem "faker"
    gem "factory_girl_rails"
    gem "ruby-debug19"
    gem "capybara", "&gt;= 0.4.1.2"
    gem 'cucumber-rails'
    gem 'database_cleaner'
    gem "rspec-rails" 
    gem 'test-unit'
  end
  
  gem "launchy"
  gem "autotest"
  gem "autotest-growl"
  gem "autotest-rails-pure"
  gem "autotest-fsevent"
  gem 'metric_fu'
  </code></pre>
  
  <p>----------------- Gemfile lock</p>
  
  <pre><code>GEM
    remote: http://rubygems.org/
    specs:
      Saikuro (1.1.0)
      ZenTest (4.5.0)
      abstract (1.0.0)
      actionmailer (3.0.7)
        actionpack (= 3.0.7)
        mail (~&gt; 2.2.15)
      actionpack (3.0.7)
        activemodel (= 3.0.7)
        activesupport (= 3.0.7)
        builder (~&gt; 2.1.2)
        erubis (~&gt; 2.6.6)
        i18n (~&gt; 0.5.0)
        rack (~&gt; 1.2.1)
        rack-mount (~&gt; 0.6.14)
        rack-test (~&gt; 0.5.7)
        tzinfo (~&gt; 0.3.23)
      activemodel (3.0.7)
        activesupport (= 3.0.7)
        builder (~&gt; 2.1.2)
        i18n (~&gt; 0.5.0)
      activerecord (3.0.7)
        activemodel (= 3.0.7)
        activesupport (= 3.0.7)
        arel (~&gt; 2.0.2)
        tzinfo (~&gt; 0.3.23)
      activeresource (3.0.7)
        activemodel (= 3.0.7)
        activesupport (= 3.0.7)
      activesupport (3.0.7)
      archive-tar-minitar (0.5.2)
      arel (2.0.10)
      arrayfields (4.7.4)
      authlogic (3.0.3)
        activerecord (&gt;= 3.0.7)
        activerecord (&gt;= 3.0.7)
      autotest (4.4.6)
        ZenTest (&gt;= 4.4.1)
      autotest-fsevent (0.2.5)
        sys-uname
      autotest-growl (0.2.9)
      autotest-rails-pure (4.1.2)
      builder (2.1.2)
      capybara (0.4.1.2)
        celerity (&gt;= 0.7.9)
        culerity (&gt;= 0.2.4)
        mime-types (&gt;= 1.16)
        nokogiri (&gt;= 1.3.3)
        rack (&gt;= 1.0.0)
        rack-test (&gt;= 0.5.4)
        selenium-webdriver (&gt;= 0.0.27)
        xpath (~&gt; 0.1.3)
      celerity (0.8.9)
      childprocess (0.1.9)
        ffi (~&gt; 1.0.6)
      chronic (0.3.0)
      churn (0.0.13)
        chronic (&gt;= 0.2.3)
        hirb
        json_pure
        main
        ruby_parser (~&gt; 2.0.4)
        sexp_processor (~&gt; 3.0.3)
      colored (1.2)
      columnize (0.3.2)
      configuration (1.2.0)
      cucumber (0.10.2)
        builder (&gt;= 2.1.2)
        diff-lcs (&gt;= 1.1.2)
        gherkin (&gt;= 2.3.5)
        json (&gt;= 1.4.6)
        term-ansicolor (&gt;= 1.0.5)
      cucumber-rails (0.4.1)
        cucumber (&gt;= 0.10.1)
        nokogiri (&gt;= 1.4.4)
        rack-test (&gt;= 0.5.7)
      culerity (0.2.15)
      database_cleaner (0.6.7)
      diff-lcs (1.1.2)
      erubis (2.6.6)
        abstract (&gt;= 1.0.0)
      factory_girl (1.3.3)
      factory_girl_rails (1.0.1)
        factory_girl (~&gt; 1.3)
        railties (&gt;= 3.0.0)
      faker (0.9.5)
        i18n (~&gt; 0.4)
      fattr (2.2.0)
      ffi (1.0.8)
      flay (1.4.2)
        ruby_parser (~&gt; 2.0)
        sexp_processor (~&gt; 3.0)
      flog (2.5.1)
        ruby_parser (~&gt; 2.0)
        sexp_processor (~&gt; 3.0)
      gherkin (2.3.8)
        json (&gt;= 1.4.6)
      haml (3.1.1)
      heroku (2.1.4)
        launchy (&gt;= 0.3.2)
        rest-client (~&gt; 1.6.1)
        term-ansicolor (~&gt; 1.0.5)
      hirb (0.4.5)
      hoptoad_notifier (2.4.9)
        activesupport
        builder
      i18n (0.5.0)
      jquery-rails (1.0.5)
        railties (~&gt; 3.0)
        thor (~&gt; 0.14)
      json (1.5.1)
      json_pure (1.5.1)
      launchy (0.4.0)
        configuration (&gt;= 0.0.5)
        rake (&gt;= 0.8.1)
      linecache19 (0.5.12)
        ruby_core_source (&gt;= 0.1.4)
      mail (2.2.19)
        activesupport (&gt;= 2.3.6)
        i18n (&gt;= 0.4.0)
        mime-types (~&gt; 1.16)
        treetop (~&gt; 1.4.8)
      main (4.4.0)
        arrayfields (&gt;= 4.7.4)
        fattr (&gt;= 2.1.0)
      metric_fu (2.1.1)
        Saikuro (&gt;= 1.1.0)
        activesupport (&gt;= 2.0.0)
        chronic (~&gt; 0.3.0)
        churn (&gt;= 0.0.7)
        flay (&gt;= 1.2.1)
        flog (&gt;= 2.3.0)
        rails_best_practices (&gt;= 0.6.4)
        rcov (&gt;= 0.8.3.3)
        reek (&gt;= 1.2.6)
        roodi (&gt;= 2.1.0)
        syntax
      mime-types (1.16)
      nokogiri (1.4.4)
      polyglot (0.3.1)
      rack (1.2.2)
      rack-mount (0.6.14)
        rack (&gt;= 1.0.0)
      rack-test (0.5.7)
        rack (&gt;= 1.0)
      rails (3.0.7)
        actionmailer (= 3.0.7)
        actionpack (= 3.0.7)
        activerecord (= 3.0.7)
        activeresource (= 3.0.7)
        activesupport (= 3.0.7)
        bundler (~&gt; 1.0)
        railties (= 3.0.7)
      rails_best_practices (0.9.0)
        activesupport
        colored
        erubis
        haml
        i18n
        ruby-progressbar
        ruby_parser
      railties (3.0.7)
        actionpack (= 3.0.7)
        activesupport (= 3.0.7)
        rake (&gt;= 0.8.7)
        thor (~&gt; 0.14.4)
      rake (0.8.7)
      rcov (0.9.9)
      reek (1.2.8)
        ruby2ruby (~&gt; 1.2)
        ruby_parser (~&gt; 2.0)
        sexp_processor (~&gt; 3.0)
      rest-client (1.6.1)
        mime-types (&gt;= 1.16)
      roodi (2.1.0)
        ruby_parser
      rspec (2.6.0)
        rspec-core (~&gt; 2.6.0)
        rspec-expectations (~&gt; 2.6.0)
        rspec-mocks (~&gt; 2.6.0)
      rspec-core (2.6.1)
      rspec-expectations (2.6.0)
        diff-lcs (~&gt; 1.1.2)
      rspec-mocks (2.6.0)
      rspec-rails (2.6.0)
        actionpack (~&gt; 3.0)
        activesupport (~&gt; 3.0)
        railties (~&gt; 3.0)
        rspec (~&gt; 2.6.0)
      ruby-debug-base19 (0.11.25)
        columnize (&gt;= 0.3.1)
        linecache19 (&gt;= 0.5.11)
        ruby_core_source (&gt;= 0.1.4)
      ruby-debug19 (0.11.6)
        columnize (&gt;= 0.3.1)
        linecache19 (&gt;= 0.5.11)
        ruby-debug-base19 (&gt;= 0.11.19)
      ruby-progressbar (0.0.10)
      ruby2ruby (1.2.5)
        ruby_parser (~&gt; 2.0)
        sexp_processor (~&gt; 3.0)
      ruby_core_source (0.1.5)
        archive-tar-minitar (&gt;= 0.5.2)
      ruby_parser (2.0.6)
        sexp_processor (~&gt; 3.0)
      rubyzip (0.9.4)
      selenium-webdriver (0.2.0)
        childprocess (&gt;= 0.1.7)
        ffi (&gt;= 1.0.7)
        json_pure
        rubyzip
      sexp_processor (3.0.5)
      sqlite3 (1.3.3)
      sqlite3-ruby (1.3.3)
        sqlite3 (&gt;= 1.3.3)
      syntax (1.0.0)
      sys-uname (0.8.5)
      term-ansicolor (1.0.5)
      test-unit (2.3.0)
      thor (0.14.6)
      treetop (1.4.9)
        polyglot (&gt;= 0.3.1)
      tzinfo (0.3.27)
      xpath (0.1.4)
        nokogiri (~&gt; 1.3)
  
  PLATFORMS
    ruby
  
  DEPENDENCIES
    authlogic
    autotest
    autotest-fsevent
    autotest-growl
    autotest-rails-pure
    capybara (&gt;= 0.4.1.2)
    cucumber-rails
    database_cleaner
    factory_girl_rails
    faker
    heroku
    hoptoad_notifier
    jquery-rails (&gt;= 0.2.6)
    launchy
    metric_fu
    rails (&gt;= 3.0.7)
    rspec-rails
    ruby-debug19
    sqlite3-ruby
    test-unit
  </code></pre>