title: Rails 3.1 and Ruby 1.9.3p125: ruby-debug19 still crashes with "Symbol not found: _ruby_threadptr_data_type"
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/8087610/ruby-debug-with-ruby-1-9-3">ruby-debug with Ruby 1.9.3?</a>  </p>
  </blockquote>
  
  
  
  <p>I had heard rumors that ruby 1.9.3p125 has a solution for the ruby-debug19 problem, so per instructions on the RVM site, I reinstalled 1.9.3:</p>
  
  <pre><code>$ rvm reinstall 1.9.3 --patch debug --force-autoconf
  $ ruby -v
    ruby 1.9.3p125 (2012-02-16 revision 34643) [x86_64-darwin11.2.0]
  </code></pre>
  
  <p>Then:</p>
  
  <pre><code>gem install ruby-debug19
  </code></pre>
  
  <p>Added this entry to my Gemfile:</p>
  
  <pre><code>gem 'ruby-debug19'
  </code></pre>
  
  <p>Then:</p>
  
  <pre><code>$ rails server -u         
  =&gt; Booting WEBrick
  =&gt; Rails 3.1.3 application starting in development on http://0.0.0.0:3000
  =&gt; Call with -d to detach
  =&gt; Ctrl-C to shutdown server
  You need to install ruby-debug to run the server in debugging mode. With gems, use 'gem install ruby-debug'
  Exiting
  </code></pre>
  
  <p>To get past this error I changed my Gemfile entry to:</p>
  
  <pre><code>gem 'ruby-debug19', :require =&gt; 'ruby-debug'
  </code></pre>
  
  <p>Now a new error from the server:</p>
  
  <pre><code>/Users/don/.rvm/gems/ruby-1.9.3-p125/gems/activesupport-3.1.3/lib/active_support/dependencies.rb:240:in `require': dlopen(/Users/don/.rvm/gems/ruby-1.9.3-p125/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.bundle, 9): Symbol not found: _ruby_threadptr_data_type (LoadError)
    Referenced from: /Users/don/.rvm/gems/ruby-1.9.3-p125/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.bundle
    Expected in: flat namespace
   in /Users/don/.rvm/gems/ruby-1.9.3-p125/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.bundle - /Users/don/.rvm/gems/ruby-1.9.3-p125/gems/ruby-debug-base19-0.11.25/lib/ruby_debug.bundle
  </code></pre>
  
  <p>I'm very confused by the hundreds of posts out there on how to handle this ruby-debug19 issue.  I was hoping it had been solved.  Apparently not.  Any suggestions?  (If anyone suggests a patch, please provide step by step instructions on how to apply it.  I've struggled with patches in the past.)</p>