Xcode 4 hangs at “Attaching to (app name)”

Question

I just upgraded to Xcode 4 and for some reason my app won\'t run in the simulator or iOS device. It was working perfectly in Xcode 3, but all of a sudden now when I press ru

Answer 1

A tip I found at the Apple Developer Forums:

Go into your ProjectName.xcodeproj/ directory and delete anything named with your userid. Re-open the project in xcode and all that will get recreated and it should work. At least it did for me.

Another tip is to manually delete the build directory.

Yet another tip is to navigate to the Organizer (Shift ⇧ Command ⌘ 2 in xcode 4), select Projects, select you application in the left hand side and then the Delete...-button to the right of Derived Data.

And never forget the universally useful tip: restart your computer and try again.

Good luck!