I receive the following error when trying to run the app on my device.
error: failed to launch \'/Users/michael/Library/Developer/Xcode/DerivedData/Build/Pro
With Mountain Lion and the latest version of Xcode (4.4.4F250), none of the suggestions in this thread worked directly (clean, clean project, remove derived data folder, etc). This sequence did. From DhilipSiva:
rm -fr ~/Library/Developer/Xcode/DerivedData (console)