问题一
Xcode Run 后控制台红色警告：
Logging Error: Failed to initialize logging system. Log messages may be missing. If this issue persists, try setting IDEPreferLogStreaming=YES in the active scheme actions environment variables.
解决办法：
- 点击Product > Scheme > Edit Scheme
- 点击Arguments > Environment Variables 添加一个新的环境变量：
Name：IDEPreferLogStreaming
Value：YES
