title: Cannot run Bundle Install on Mac OS Mountain Lion due to JSON v(1.7.3) gem error
body: <p>first thing is first, I HAVE the command line tools from xcode installed on my mac, so that is not the issue. Please don't point me to the 50 other posts about this, as they all just say "install the command line tools".</p>
  
  <p>This is the error I get when I run <code>bundle install</code></p>
  
  <pre><code>Installing json (1.7.3) with native extensions 
  Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.
  
      /usr/local/rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb 
  creating Makefile
  
  make
  compiling parser.c
  make: gcc-4.2: No such file or directory
  make: *** [parser.o] Error 1
  
  
  Gem files will remain installed in /usr/local/rvm/gems/ruby-1.9.3-p194/gems/json-1.7.3 for inspection.
  Results logged to /usr/local/rvm/gems/ruby-1.9.3-p194/gems/json-1.7.3/ext/json/ext/parser/gem_make.out
  An error occured while installing json (1.7.3), and Bundler cannot continue.
  Make sure that `gem install json -v '1.7.3'` succeeds before bundling.
  </code></pre>
  
  <p>I've been looking all over the place, and some people have told me to install the <code>install ruby-dev</code> command, but I haven't found a mac solution, as I don't have <code>apt-get</code> installed.</p>
  
  <p>Besides, looking at the error, it looks like there is a directory missing where the files are trying to go. I'm not sure what to even do about that? </p>
  
  <p>I haven't been able to find a way to reinstall ruby altogether either. </p>
  
  <p>Any easy solutions to this? </p>
  
  <p>Thanks a ton!</p>
  
  <p>EDIT: Here is a list of my local gems, I am running GCC version 4.2.1, and Ruby version 1.9.3-p194</p>
  
  <p>What's wierd is that there is already a newer version of JSON installed (1.7.5), so I don't know why it's trying to install 1.7.3, maybe there is a gem that has a dependency? I wish I could just skip that gem, and install the rest of the bundle. The dependency should be met with 1.7.5, unless a gem is calling for a specific version, right?</p>
  
  <pre><code>*** LOCAL GEMS ***
  
  actionmailer (3.2.13, 3.2.7, 3.2.6)
  actionpack (3.2.13, 3.2.7, 3.2.6)
  activemodel (3.2.13, 3.2.7, 3.2.6)
  activerecord (3.2.13, 3.2.7, 3.2.6)
  activeresource (3.2.13, 3.2.7, 3.2.6)
  activesupport (3.2.13, 3.2.7, 3.2.6)
  appscrolls (0.9.0, 0.8.4)
  arel (3.0.2)
  bcrypt-ruby (3.0.1)
  bourne (1.4.0, 1.2.1)
  builder (3.2.0, 3.0.0)
  bundler (1.3.4, 1.1.5)
  coffee-rails (3.2.2)
  coffee-script (2.2.0)
  coffee-script-source (1.6.1, 1.3.3)
  comp_tree (1.1.3)
  devise (2.2.3, 2.1.2)
  draper (1.1.0)
  erubis (2.7.0)
  execjs (1.4.0)
  factory_girl (4.2.0)
  factory_girl_rails (4.2.1)
  hike (1.2.1)
  i18n (0.6.4, 0.6.1, 0.6.0)
  journey (1.0.4)
  jquery-rails (2.2.1, 2.1.1, 2.0.2)
  js-routes (0.8.7)
  json (1.7.5)
  mail (2.5.3, 2.4.4)
  metaclass (0.0.1)
  mime-types (1.21, 1.19)
  mocha (0.13.3, 0.12.7)
  multi_json (1.7.1, 1.3.6)
  orm_adapter (0.4.0)
  polyglot (0.3.3)
  pure (0.2.2)
  rack (1.5.2, 1.4.5, 1.4.1)
  rack-cache (1.2)
  rack-ssl (1.3.3, 1.3.2)
  rack-test (0.6.2, 0.6.1)
  rails (3.2.13, 3.2.7, 3.2.6)
  railties (3.2.13, 3.2.7, 3.2.6)
  rake (10.0.3, 0.9.2.2)
  rdoc (4.0.0, 3.12)
  request_store (1.0.5)
  ruby_parser (3.1.2)
  rubygems-bundler (1.1.1, 1.0.3)
  rvm (1.11.3.6, 1.11.3.5)
  sass (3.2.7, 3.2.1, 3.1.20)
  sass-rails (3.2.6, 3.2.5)
  sexp_processor (4.2.0)
  shoulda (3.4.0)
  shoulda-context (1.0.2)
  shoulda-matchers (1.5.1, 1.5.0)
  simple_form (2.1.0, 2.0.2)
  sprockets (2.9.0, 2.2.2, 2.1.3)
  sqlite3 (1.3.6)
  state_machine (1.1.2)
  thor (0.17.0, 0.16.0, 0.15.4)
  tilt (1.3.6, 1.3.3)
  treetop (1.4.12, 1.4.10)
  tzinfo (0.3.37, 0.3.33)
  uglifier (1.3.0, 1.2.7)
  warden (1.2.1)
  </code></pre>