Xcode 4: Build Failed, No Issues

Question

The app works fine in the simulator, builds and runs.

When I attach my device (iPhone 3GS running iOS 4.3) and target the iPhone, the result is \"Build failed\" with

Answer 1

After going though all these answers, I had the exact same issue, but something different solved it for me.

The Problem:

Build failed without issues after refactoring. (Renamed a class using Edit -> Refactor -> Rename).

The Dumbest Solution Ever:

Go refactor (rename) something else (-_-"). After doing that, the error was that Xcode failed to rename all appropriate files, and didn't show errors. Then, after another refactor, the errors from the previous refactor appeared.