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

I was just playing with adding multiple projects inside a workspace and got this problem. I have a simple library in one of the projects and I was building and I added an iOS window based target to test it. I deleted the first target I made for this to rename it. After reading this I tried removing xcuserdata from inside the .xcodeproj package and that fixed my problem. I hope this helps someone else. Running Xcode 4.1 on OS X 10.7.1.