title: Debugger cannot compile on Ruby 2.0
body: <p>Originally posted here: "<a href="https://stackoverflow.com/questions/15200165/how-to-use-the-debugger-with-ruby-2-0/">How to use the debugger with Ruby 2.0?</a>"</p>
  
  <p>I keep ending up back here, but I have a different problem. I don't have the option to change to Byebug right now. We are currently stuck on "debugger" for now, and I cannot install it.</p>
  
  <pre><code>Building native extensions.  This could take a while...
  ERROR:  Error installing debugger:
    ERROR: Failed to build gem native extension.
  
      /Users/mbridges/.rbenv/versions/2.0.0-p247/bin/ruby extconf.rb
  *** extconf.rb failed ***
  Could not create Makefile due to some reason, probably lack of necessary
  libraries and/or headers.  Check the mkmf.log file for more details.  You may
  need configuration options.
  
  Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/Users/mbridges/.rbenv/versions/2.0.0-p247/bin/ruby
  /Users/mbridges/.rbenv/versions/2.0.0-p247/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:51:in `require': cannot load such file -- debugger/ruby_core_source (LoadError)
    from /Users/mbridges/.rbenv/versions/2.0.0-p247/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:51:in `require'
    from extconf.rb:16:in `&lt;main&gt;'
  </code></pre>
  
  <p>Anyone have any ideas?</p>