title: how do I install ruby-debug in ruby 1.9.3 / Rails 3.2.1
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/9442200/rails-3-1-and-ruby-1-9-3p125-ruby-debug19-still-crashes-with-symbol-not-found">Rails 3.1 and Ruby 1.9.3p125: ruby-debug19 still crashes with &ldquo;Symbol not found: _ruby_threadptr_data_type&rdquo;</a>  </p>
  </blockquote>
  
  
  
  <p>I'm done with printing to the console -- I want to move up to the 20th century and start using a debugger!!  But how do I install ruby-debug?  The native compilation of <code>ruby-debug.c</code> fails when I try to install the ruby-debug19 gem.  I've looked over other SO postings and haven't found the answer yet...</p>
  
  <ul>
  <li>I am using Ruby 1.9.3-p0</li>
  <li>I am using Rails 3.2 (with Gemfile, of course)</li>
  <li>I am NOT using RVM -- instead, I have a fully sandboxed directory containing all executables, gems, sources, etc.  I refer to it as $SANDBOX below...</li>
  </ul>
  
  <h2>bundle install doesn't work</h2>
  
  <p>If I add ruby-debug19 to my Gemfile and do <code>bundle install</code>, it fails during build with <code>conflicting types for 'rb_iseq_compile_with_option'</code>:</p>
  
  <pre><code># file: Gemfile
  ...
  group :development do
    gem 'ruby-debug19'
  end
  ...
  
  % bundle install
  ...
  Installing ruby-debug-base19 (0.11.25) with native extensions 
  Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
          /Users/r/Developer/Topaz/usr/bin/ruby extconf.rb 
  ...
  ruby_debug.c:29: error: conflicting types for 'rb_iseq_compile_with_option'
  $SANDBOX/usr/include/ruby-1.9.1/ruby-1.9.3-p0/vm_core.h:505: error: previous declaration of 'rb_iseq_compile_with_option' was here
  ...
  make: *** [ruby_debug.o] Error 1
  </code></pre>
  
  <h2>gem install ruby-debug from the command line doesn't work</h2>
  
  <p>If I try building the gem from the command line, using the --with-ruby-include argument pointing at the <code>include</code> directory for the current ruby, I get the same error:</p>
  
  <pre><code>% gem install ruby-debug19 -- --with-ruby-include=$SANDBOX/packages/ruby-1.9.3-p0
  Building native extensions.  This could take a while...
  ERROR:  Error installing ruby-debug19:
          ERROR: Failed to build gem native extension.
  
          $SANDBOX/usr/bin/ruby extconf.rb --with-ruby-include=$SANDBOX/packages/ruby-1.9.3-p0/include
  checking for rb_method_entry_t.body in method.h... no
  checking for vm_core.h... yes
  checking for iseq.h... yes
  checking for insns.inc... yes
  checking for insns_info.inc... yes
  checking for eval_intern.h... yes
  creating Makefile
  
  make
  compiling breakpoint.c
  compiling ruby_debug.c
  ruby_debug.c:29: error: conflicting types for 'rb_iseq_compile_with_option'
  $SANDBOX/usr/include/ruby-1.9.1/ruby-1.9.3-p0/vm_core.h:505: error: previous declaration of 'rb_iseq_compile_with_option' was here
  </code></pre>
  
  <h2>what am I missing?</h2>
  
  <p>Is --with-ruby-include expecting something different?  Is the current ruby-debug19 broken?</p>