出现这种警告
Your Podfile has had smart quotes sanitised. To avoid issues in the future, you should not use TextEdit for editing it. If you are not using TextEdit, you should turn off smart quotes in your editor of choice.
解决办法：不要使用文本编辑去编辑Podfile，使用Xcode编辑，或者使用终端敲命令去编辑。或者输入格式错误，没输入运行版本：$platform:ios, ‘9.0‘
1 [!] The `Paopao [Debug]` target overrides the `PODS_ROOT` build setting defined in `Pods/Target Support Files/Pods/Pods.debug.xcconfig'. This can lead to problems with the CocoaPods installation
- Use the `$(inherited)` flag, or
- Remove the build settings from the target.
[!] The `Paopao [Debug]` target overrides the `OTHER_LDFLAGS` build setting defined in `Pods/Target Support Files/Pods/Pods.debug.xcconfig'. This can lead to problems with the CocoaPods installation
- Use the `$(inherited)` flag, or
- Remove the build settings from the target.
[!] The `Paopao [Release]` target overrides the `PODS_ROOT` build setting defined in `Pods/Target Support Files/Pods/Pods.release.xcconfig'. This can lead to problems with the CocoaPods installation
- Use the `$(inherited)` flag, or
- Remove the build settings from the target.
[!] The `Paopao [Release]` target overrides the `OTHER_LDFLAGS` build setting defined in `Pods/Target Support Files/Pods/Pods.release.xcconfig'. This can lead to problems with the CocoaPods installation
- Use the `$(inherited)` flag, or
- Remove the build settings from the target.产生此警告的原因是项目 Target 中的一些设置，CocoaPods 也做了默认的设置，如果两个设置结果不一致，就会造成问题。
我想要使用 CocoaPods 中的设置，分别在我的项目中定义PODS_ROOT 和 Other Linker Flags的地方，把他们的值用$(inherited)替换掉，进入终端，执行
pod update警告没了
我个人更喜欢一种简单粗暴的方法：
点击项目文件 project.xcodeproj，右键显示包内容，用文本编辑器打开project.pbxproj，删除OTHER_LDFLAGS的地方，保存，pod update,警告没了。。。。(注意：OTHER_LDFLAGS 有两个地方：debug和release)