Just now, I updated my AWS SDKs, which I regretted so much. I first saw this when the pods were updated:
dyld: warning, LC_RPATH @executable_path /../../../../../../../ SharedFrameworks in /Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/ ../../..//DVTInstrumentsFoundation.framework/Versions/A/DVTInstrumentsFoundation is ignored in the restricted program due to @executable_path dyld: warning, LC_RPATH @executable_path /../ lib in /Applications/Xcode.app/Contents/ Frameworks / IDEFoundation.framework / Versions / A /../../../../ Developer / Toolchains / XcodeDefault. xctoolchain / usr / lib / libclang.dylib is ignored in the restricted program due to @executable_path
dyld: warning, LC_RPATH @executable_path /../ lib in /Applications/Xcode.app/Contents/Frameworks/IDEFoundation.framework/Versions/A/../../../../Developer/Toolchains/XcodeDefault. xctoolchain / usr / lib / libLTO.dylib is ignored in the restricted program due to @executable_path
dyld: warning, LC_RPATH @executable_path /../ Frames in /Applications/Xcode.app/Contents/PlugIns/Xcode3Core.ideplugin/Contents/MacOS/Xcode3Core are ignored in the restricted program due to @executable_path
Then, when I opened my project and built, I had so many build crashes complaining about the same Duplicate interface for class XXX :
I tried many solutions, reinstalled SDS SDKs, reinstalled cocoapods, downgraded coco files to 0.38.2, downgraded AWS SDK levels to 2,6,6, but none help. If I comment on the import in the Objective-C bridge header, I don't have these errors, but Xcode just complains that it won't find some classes used in the codes. But I do not think that commenting on them is the right decision. 
Well, I searched for https://github.com/CocoaPods/CocoaPods/issues/4302 , and it looks like this might be a problem with cocoapods?
Anyone have an idea on this? Thanks.