今天刚开始研究cocos2d，不是2ds哈，按网上的教程，下了个cocos2d installer 3.1.0安装，然后打开xcode7 ，选cocos，新建工程，就是cocos2d自己那个hello world程序，直接
run，然后就报错了，错误主要如下图
Undefined symbols for architecture x86_64:
“_AVAudioSessionCategoryAmbient”, referenced from:
- in OALAudioSession.o
- in OALAudioSession.o
“_AVAudioSessionCategoryAudioProcessing”, referenced from:
- in OALAudioSession.o
ld: symbol(s) not found for architecture x86_64
error: linker command failed with exit code 1 (use -v to see invocation)