xcode 编译时有相同的类，导致冲突，编译错误

-->相同类，不同地址

duplicate symbol _OBJC_CLASS_$_TTDataReport in:
    /Users/youlinmac/Library/Developer/Xcode/DerivedData/client-afzozhjxxecgofdppfwzdmoalrxm/Build/Intermediates/client.build/Debug-iphoneos/ttaxx.build/Objects-normal/arm64/TTDataReport-CE222134F89CC50.o
    /Users/youlinmac/Library/Developer/Xcode/DerivedData/client-afzozhjxxecgofdppfwzdmoalrxm/Build/Intermediates/client.build/Debug-iphoneos/ttaxx.build/Objects-normal/arm64/TTDataReport-6F254BC198D6539.o 

找了半天，原来是在其他文件夹有一个跟报错类一样的类。全局搜一下就出来了。