七牛使用cocoapods导入后编译不通过报错undefined symbols for architecture armv7 referenced from

从昨天导入sdk后就一直编译不通过，网上各种查找原因，很多人说的缺库，但是又没说缺什么库，然后自己也以为是缺库，折腾了好久，最后还是没从这里突破，实在无奈之下，决定重新导入，删除pods的相关文件，重新来一遍，最后在导入完之后，有个警告

警告如下

[!] The `XXXX [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 `XXXX [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

根据上面的提示重新设置了flag的值，ok,编译没问题了

博文参考
http://www.cnblogs.com/ihojin/p/xcode6-cocoapods-error.html