如果你重新运行了，想查看打印记录

首先将.xcactivitylog转化为.log
终端输入：

cd ~/Library/Developer/Xcode/DerivedData//Logs/Debug/
EXT=".xcactivitylog"
for LOG in *.xcactivitylog; do
    NAME=`basename $LOG $EXT`
    gunzip -c -S $EXT "${NAME}${EXT}" > "${NAME}.log"
done

然后打开Debug文件夹查看.log即可
~/Library/Developer/Xcode/DerivedData//Logs/Debug/