Xcode 6 Swift code completion not working

Question

Using Xcode 6 GM seed my code completion has stopped working. It was working the other day. I was trying to get the unwind segue work around to work. I had made an Objc head

Answer 1

Go to Xcode menu, then Window -> Organizer, then select Projects. Pick your project and press on delete button beside dervied data Then restart Xcode

That solution worked with me on Xcode 6.1