Xcode 7.3: import Module displayed with strikethrough

Question

After upgrading Xcode to 7.3, I just found that some modules are stricken out while importing, like in this screenshot:

But after adding the module (so just pressing enter) everything is fine. What does that mean? The module here is written in Swift and works fine.

Answer 1

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.

Answer 2

The strikethrough occurs if you try to import a module that has already been imported by your file or module:

In this case, I have already imported Foundation (which implicitly imports CoreFoundation), so Xcode is telling you that there is no need to import either module again.