title: Gem Install Debugger Error
body: <p>I am running Rails v4.0.2 on Mac OS 10.9.2 and I had everything smoothly. All of a sudden I'm getting an error saying gems are missing when I try <code>rails server</code>. I run bundle install and this is the output:</p>
  
  <pre><code>Fetching gem metadata from https://rubygems.org/.......
  Fetching additional metadata from https://rubygems.org/..
  Using rake 10.1.1
  Using i18n 0.6.9
  Using minitest 4.7.5
  Using multi_json 1.9.0
  Using atomic 1.1.16
  Using thread_safe 0.2.0
  Using tzinfo 0.3.39
  Using activesupport 4.0.2
  Using builder 3.1.4
  Using erubis 2.7.0
  Using rack 1.5.2
  Using rack-test 0.6.2
  Using actionpack 4.0.2
  Using mime-types 1.25.1
  Using polyglot 0.3.4
  Using treetop 1.4.15
  Using mail 2.5.4
  Using actionmailer 4.0.2
  Using activemodel 4.0.2
  Using activerecord-deprecated_finders 1.0.3
  Using arel 4.0.2
  Using activerecord 4.0.2
  Using encryptor 1.3.0
  Using attr_encrypted 1.3.2
  Using awesome_print 1.2.0
  Using bcrypt 3.1.7
  Using bcrypt-ruby 3.1.5
  Using net-ssh 2.8.0
  Using net-scp 1.1.2
  Using tins 1.0.0
  Using term-ansicolor 1.3.0
  Using sshkit 1.3.0
  Using capistrano 3.1.0
  Using capistrano-bundler 1.1.2
  Using capistrano-rails 1.1.1
  Using climate_control 0.0.3
  Using cocaine 0.5.3
  Using coderay 1.1.0
  Using coffee-script-source 1.7.0
  Using execjs 2.0.2
  Using coffee-script 2.2.0
  Using thor 0.18.1
  Using railties 4.0.2
  Using coffee-rails 4.0.1
  Using columnize 0.3.6
  Using currencies 0.4.2
  Using countries 0.9.3
  Using debugger-linecache 1.2.0
  Using debugger-ruby_core_source 1.3.2
  
  Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
  
      /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/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/aaronpardes/.rvm/rubies/ruby-2.1.2/bin/ruby
  /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1573:in `stat': No such file or directory @ rb_file_s_stat - ./212/ruby_debug.h (Errno::ENOENT)
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1573:in `block in fu_each_src_dest'
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1587:in `fu_each_src_dest0'
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1571:in `fu_each_src_dest'
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:399:in `cp'
      from extconf.rb:83:in `block in &lt;main&gt;'
      from extconf.rb:82:in `each'
      from extconf.rb:82:in `&lt;main&gt;'
  
  extconf failed, exit code 1
  
  Gem files will remain installed in /Users/aaronpardes/.rvm/gems/ruby-2.1.2@ocx/gems/debugger-1.6.6 for inspection.
  Results logged to /Users/aaronpardes/.rvm/gems/ruby-2.1.2@ocx/extensions/x86_64-darwin-13/2.1.0-static/debugger-1.6.6/gem_make.out
  An error occurred while installing debugger (1.6.6), and Bundler cannot continue.
  Make sure that `gem install debugger -v '1.6.6'` succeeds before bundling.
  </code></pre>
  
  <p>When I try to run <code>gem install debugger -v '1.6.6'</code> I get the following output:</p>
  
  <pre><code>Building native extensions.  This could take a while...
  ERROR:  Error installing debugger:
      ERROR: Failed to build gem native extension.
  
      /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/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/aaronpardes/.rvm/rubies/ruby-2.1.2/bin/ruby
  /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1573:in `stat': No such file or directory @ rb_file_s_stat - ./212/ruby_debug.h (Errno::ENOENT)
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1573:in `block in fu_each_src_dest'
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1587:in `fu_each_src_dest0'
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:1571:in `fu_each_src_dest'
      from /Users/aaronpardes/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/fileutils.rb:399:in `cp'
      from extconf.rb:83:in `block in &lt;main&gt;'
      from extconf.rb:82:in `each'
      from extconf.rb:82:in `&lt;main&gt;'
  
  extconf failed, exit code 1
  
  Gem files will remain installed in /Users/aaronpardes/.rvm/gems/ruby-2.1.2@ocx/gems/debugger-1.6.6 for inspection.
  Results logged to /Users/aaronpardes/.rvm/gems/ruby-2.1.2@ocx/extensions/x86_64-darwin-13/2.1.0-static/debugger-1.6.6/gem_make.out
  </code></pre>
  
  <p>I am very confused why this error came up all of a sudden. I have been up and running without issue for weeks. I've tried creating a new gemset with rvm and still encounter the same issue. After searching around I found recommendations to update dependencies first and then try <code>bundle install</code> but this did not solve the issue. </p>