If you are using CocoaPods and a recent pod install produced a strange result like:
$ pod install Analyzing dependencies [!] Pod::Executable pull A AAShareBubbles/1.0.2/AAShareBubbles.podspec A ABContactHelper/0.1/ABContactHelper.podspec A ABPadLockScreen/3.0.0/ABPadLockScreen.podspec ... A wpxmlrpc/0.4/wpxmlrpc.podspec A ym/1.2.6/ym.podspec A zipzap/6.0/zipzap.podspec Pull is not possible because you have unmerged files. Please, fix them up in the work tree, and then use 'git add/rm <file>' as appropriate to mark resolution, or use 'git commit -a'.
… resetting the repository might help:
$ pod repo remove master $ pod setup