How to Empty Caches and Clean All Targets Xcode 4 – Stack Overflow

Command-Option-Shift-K to clean out the build folder. Even better, quit Xcode and clean out ~/Library/Developer/Xcode/DerivedData manually. Remove all its contents because there’s a bug where Xcode will run an old version of your project that’s in there somewhere. […]

In the simulator, choose iOS Simulator > Reset Content and Settings.

[…]

caching – How to Empty Caches and Clean All Targets Xcode 4 – Stack Overflow.