RubyMotion now uses LLDB for debugging. Previously it used GDB. If you’re getting random crashes with little or no backtrace it may be down to a memory allocation issue. Launch your application with the debugger running via: $ bundle exec rake debug=1 NSZombieEnabled=YES MallocStackLogging=1 Trigger your bug and you should get output in Terminal like this: 2013-10-16 10:17:19.594 YourAppName[68253