title: ERROR: 'rake/rdoctask' is obsolete and no longer supported. Use 'rdoc/task' (available in RDoc 2.4.2+) instead
body: <p>Seems the last post for this problem was closed for one reason or another so I'll try my luck...</p>
  
  <p>I'm trying to run a simple "rake db:migrate" command. When I do, I get the error in the title.  Yes, the solution "appears" obvious but it's not because I don't my Rakefile does not contain any references to 'rake/rdoctask'. It seems to be coming from documentation.rake but when I try to change that file as recommended by the error, I get a different error. I have found a couple of posts declaring this to be a known issue but nothing I've found indicates how to fix or work around this.</p>
  
  <p>Does anyone have any ideas how to fix it?  Below is the output from the rake command with a --trace:</p>
  
  <pre><code>$ rake --trace db:migrate
  rake aborted!
  ERROR: 'rake/rdoctask' is obsolete and no longer supported. Use 'rdoc/task' (available in RDoc 2.4.2+) instead.
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/rdoctask.rb:1:in `&lt;top (required)&gt;'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks/documentation.rake:2:in `require'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks/documentation.rake:2:in `&lt;top (required)&gt;'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:15:in `load'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:15:in `block in &lt;top (required)&gt;'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:6:in `each'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/tasks.rb:6:in `&lt;top (required)&gt;'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:213:in `require'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:213:in `initialize_tasks'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:139:in `load_tasks'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/railties-3.0.3/lib/rails/application.rb:77:in `method_missing'
      C:/developer/skknobara/Rakefile:7:in `&lt;top (required)&gt;'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/rake_module.rb:25:in `load'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/rake_module.rb:25:in `load_rakefile'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:583:in `raw_load_rakefile'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:89:in `block in load_rakefile'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:88:in `load_rakefile'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:72:in `block in run'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'
      C:/Programs/Ruby193/lib/ruby/gems/1.9.1/gems/rake-10.0.3/bin/rake:33:in `&lt;top (required)&gt;'
      C:/Programs/Ruby193/bin/rake:23:in `load'
      C:/Programs/Ruby193/bin/rake:23:in `&lt;main&gt;'
  </code></pre>
  
  <hr>
  
  <p>I discovered that I had rails 3.0.3 in my Gemfile so I changed it to 3.2.9, but now when I run rake db:migrate I get:</p>
  
  <pre><code>rake aborted!
  Bundler could not find compatible versions for gem "rack":
    In Gemfile:
      rails (= 3.2.9) x86-mingw32 depends on
        rack (~&gt; 1.4.0) x86-mingw32
  
      rack (1.2.5)
  </code></pre>
  
  <p>I'm not sure what the error means but "gem list rack" shows I have both 1.4.1 and 1.4.0 installed.  My Gemfile is pretty simple:</p>
  
  <pre><code>gem 'rails', '3.2.9'
  gem 'rack','&lt; 1.4.1'
  gem 'mysql2', '&lt; 0.3'
  </code></pre>
  
  <p>Any thoughts?</p>