Error "Use of undeclared type" in Xcode won't go away

Question

I moved a Swift class declaration from one file to another and now Xcode 8.2.1 keeps nagging me with red errors "Use of undeclared type" wherever I use this class. The project does compile & run without errors, but when I edit the code the error messages pop up again.

I already

• cleaned the project
• cleaned the build folder
• deleted DerivedData manually
• restarted Xcode
• restarted my Mac

Is there anything else I can do to get rid of these messages?

Answer 1

The solution is to include the new file that you moved your class to in your test target.