1：Xcode报错You don’t have permission.
原因1：
将"Default compiler (Apple LLVM 9.0)"改成“Default compiler (Apple LLVM 9.0)”
** 注：这个方法好像不行*
原因2：
添加了两个plist文件，把新的删了
2：OBJC_CLASS$_某文件名", referenced from:
原因1. .m文件没有导入
在Build Phases里的Compile Sources 中添加报错的文件
原因2. .framework文件没有导入
**
（在xcode9.0中，手动拖的SDK需要直接导入到“Link Binary With ...”）
静态库编译时往往需要一些库的支持，查看你是否有没有导入的库文件
同样是在Build Phases里的Link Binary With Libraries中添加
3：'sharedApplication' is unavailable: not available on iOS (App Extension) - Use view controller based
/Users/lirong/Documents/git/ios/Pods/MBProgressHUD/MBProgressHUD.m:760:54: 'sharedApplication' is unavailable: not available on iOS (App Extension) - Use view controller based solutions where appropriate instead.
今天运行Xcode一直报这个错误，然后去搜索解决答案，各种都是让把cocoapods卸载了重装的，试了都不成功。最后终于找到解决答案。
To remove sharedApplication issue from CocoaPods Libraries you just need to change Build Options within Build Settings for your pod.
Just type to search Require Only App-Extension-Safe API and then change the value to NO as it is on the image below:
在pods Target里面，点击buildSettings 然后把Require Only App-Extension-Safe API 然后把YES改为NO即可。工程同理
