参考：/YanceChen/article/details/67636498?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.baidujs&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.baidujs
/ws1836300/article/details/52953410?utm_medium=distribute.pc_relevant.none-task-blog-baidujs_title-2&spm=1001.2101.3001.4242
/questions/64974291/xcode-12-3-beta-failed-to-prepare-device-for-development
1.复制一份旧的SDK，并重新命名为真机测试需要的SDK版本
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer
2. 进入刚刚复制的sdk文件夹下，把里面所有跟版本相关的改成当前版本
3.去这里下载对应的真机调试包，然后复制到下面路径里
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport
4. 再次运行可能会报错“Errors were encountered while preparing your device for development. Please check the Devices and Simulators Window”。
5. 但是现在还是没办法解决，一调试就断开连接，擦
