RubyMotionエラー

[21:41:03]$ git clone https://github.com/tnantoka/RubyMotionApps.git tnantoka
[21:41:03]$ cd tnantoka/Browser
[21:30:34]$ rake
===============================================================================
It appears that you have a version of Xcode installed in /Applications that has
not been set as the default version. It is possible that RubyMotion may be
using old versions of certain tools which could eventually cause issues.

To fix this problem, you can type the following command in the terminal:
    $ sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
===============================================================================
     Build ./build/iPhoneSimulator-5.1-Development
    Create ./build/iPhoneSimulator-5.1-Development/Browser.app/PkgInfo
    Create ./build/iPhoneSimulator-5.1-Development/Browser.dSYM
  Simulate ./build/iPhoneSimulator-5.1-Development/Browser.app
*** simulator session started with error: Error Domain=DTiPhoneSimulatorErrorDomain Code=1 "Unknown error." UserInfo=0x10040df90 {NSLocalizedDescription=Unknown error., DTiPhoneSimulatorUnderlyingErrorCodeKey=-1}
rake aborted!
Command failed with status (1): [DYLD_FRAMEWORK_PATH="/Applications/Xcode.a...]

Tasks: TOP => default => simulator
(See full trace by running task with --trace)
[21:39:45]$ sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
Password:
[21:41:01]$ rake
     Build ./build/iPhoneSimulator-5.1-Development
  Simulate ./build/iPhoneSimulator-5.1-Development/Browser.app
*** simulator session started with error: Error Domain=DTiPhoneSimulatorErrorDomain Code=1 "Unknown error." UserInfo=0x100424a70 {NSLocalizedDescription=Unknown error., DTiPhoneSimulatorUnderlyingErrorCodeKey=-1}
rake aborted!
Command failed with status (1): [DYLD_FRAMEWORK_PATH="/Applications/Xcode.a...]

Tasks: TOP => default => simulator
(See full trace by running task with --trace)