create a cocos2d-x-3.0 project in Xcode

STEP1: Open Terminal

SETP2: Run setup.py

SETP3: Run source /Users/your_user/.bash_profile( so that environment variables are actually updated)

SETP4: Run cocos new my game -p com.your_company.mygame -l cpp -d /diretory_to_your_game