Xcode 6 Beta: No such module 'Cocoa'

I'm trying to use the standard Cocoa library in a swift file in Xcode 6 Beta. I followed this instructions but when I import the library

import Cocoa

XCode complains with the error

No such module 'Cocoa'

I also tried with the REPL and I have no problems at all. I suppose it's a bug, cause I started different projects and only sometimes I get this error. Any suggestions? I'm using Mavericks (10.9.3)

Replace

import Cocoa

With:

import UIKit

You can't import Cocoa from an iOS playground or application. Make sure your code is running in a Cocoa playground (select OS X > Source in the new file dialog).

From your question, it seems that you are trying to add Cocoa class into your iOS Application instead of Cocoa Touch class. So this is not a bug of Xcode.

Be sure to select template which are under the iOS section shown in the following screenshot, as we are choosing it for an iOS Application.