增加xcode真机运行包 1.1 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 1.2. 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 1.3.去这里下载对应的真机调试包，然
iOS开发之Xcode工程编译报错The Xcode build system has crashed. Please close and reopen your workspace 解决：删除Xcode下的DerivedData文件 /Users/用户名/Library/Developer/Xcode/DerivedData
After modifying system headers, please delete the module cache at '/Users/XXX/Library/Developer/Xcode/DerivedData/XXXX/2ZMDAUJMMHSDC' 解决的方法：前往 '/Users/XXX/Library/Developer/Xcode/DerivedData/XXX/2ZMDAUJMMHSDC 这个目录，删除其目录中的内容。然后执行a
