title: RubyMotion and CocoaPods problems
body: <p>I'm various issues getting CocoaPods dependencies to work in RubyMotion. Firstly, if I add <code>dependency 'JSONKit'</code> to my Rakefile and then run <code>rake</code> it get's aborted with a <code>can't convert Pathname into String</code> error. <code>rake --trace</code> then produces the following output:</p>
  
  <pre><code>** Invoke default (first_time)
  ** Invoke simulator (first_time)
  ** Invoke build:simulator (first_time)
  ** Execute build:simulator
  /usr/bin/gen_bridge_metadata --format complete --no-64-bit --cflags "-I. -I." JSONKit.h -o "JSONKit.bridgesupport"
  invalid option: --no-64-bit
  Usage: gen_bridge_metadata [options] &lt;headers...&gt;
  Use the `-h' flag or consult gen_bridge_metadata(1) for help.
  rake aborted!
  Command failed with status (1): [/usr/bin/gen_bridge_metadata --format comp...]
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/file_utils.rb:53:in `block in create_shell_runner'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/file_utils.rb:45:in `call'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/file_utils.rb:45:in `sh'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/file_utils_ext.rb:39:in `sh'
  /Library/RubyMotion/lib/motion/project/vendor.rb:93:in `block in build_static'
  /Library/RubyMotion/lib/motion/project/vendor.rb:34:in `chdir'
  /Library/RubyMotion/lib/motion/project/vendor.rb:34:in `build_static'
  /Library/RubyMotion/lib/motion/project/vendor.rb:23:in `build'
  /Library/RubyMotion/lib/motion/project/builder.rb:37:in `block in build'
  /Library/RubyMotion/lib/motion/project/builder.rb:36:in `each'
  /Library/RubyMotion/lib/motion/project/builder.rb:36:in `build'
  /Library/RubyMotion/lib/motion/project/app.rb:50:in `build'
  /Library/RubyMotion/lib/motion/project.rb:33:in `block (2 levels) in &lt;top (required)&gt;'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:205:in `call'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:205:in `block in execute'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:200:in `each'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:200:in `execute'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:158:in `block in invoke_with_call_chain'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:151:in `invoke_with_call_chain'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:176:in `block in invoke_prerequisites'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:174:in `each'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:174:in `invoke_prerequisites'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:157:in `block in invoke_with_call_chain'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:151:in `invoke_with_call_chain'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:176:in `block in invoke_prerequisites'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:174:in `each'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:174:in `invoke_prerequisites'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:157:in `block in invoke_with_call_chain'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:151:in `invoke_with_call_chain'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/task.rb:144:in `invoke'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:116:in `invoke_task'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:94:in `block (2 levels) in top_level'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:94:in `each'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:94:in `block in top_level'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:133:in `standard_exception_handling'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:88:in `top_level'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:66:in `block in run'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:133:in `standard_exception_handling'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/rake/application.rb:63:in `run'
  /Users/xxxx/.rbenv/versions/1.9.3-p194/bin/rake:32:in `&lt;main&gt;'
  Tasks: TOP =&gt; default =&gt; simulator =&gt; build:simulator
  </code></pre>
  
  <p>The vendor directory in the project contains various JSONKit files.</p>
  
  <p>Secondly, in another RubyMotion app, if I add <code>dependency 'Nimbus'</code> to my Rakefile and then run <code>rake</code> the app builds but errors out with uninitialized constant errors when I try to use anything Nimbus-related in my code and no vendor directory is created.</p>
  
  <p>What is the problem in these two instances?</p>