Debug Problems under os x

Hello I tried to debug a simple sample code in nsight under os x and I got following error (I’ve put a link to error’s image):
http://d.pr/i/IYMk
Can anybody give me a hint?

Your cuda-gdb is not properly configured. See Setting Up the Debugger Environmnet / Mac OS X in cuda-gdb manual.

Please note that using visual debugger requires a multi-GPU system, otherwise OS X will terminate kernels being debugged.