Xcode 7.3: Import Module Displayed with Strikethrough

Xcode 7.3: import Module displayed with strikethrough

This is a bug. We have fixed it in 218010af, which should be included in the Swift 2.2.1 release and is included in the 2016-04-12-a developer snapshot.

What is this red line through the Xcode import auto suggest

I think it might just be a bug with Xcode. Ever since the update, I have noticed there are red strike-thoughs on some of the frameworks.

UIKit strike-thru

As long as it works when you compile, everything should be fine.

unit test module import throws undefined symbol error

If you created a multiplatform project, turns out that the default test target is a UI test and not a unit test.
Try adding a new test target of type unit test.
See this answer: https://developer.apple.com/forums/thread/665120