Xcode 11 Beta 3, build error “Unknown attribute 'State'”, “Use of undeclared type 'View'” etc

Question

I build an app with the 2nd beta of Xcode 11, using SwiftUI, and everything worked completely fine, but now, with the 3rd beta, the app isn\'t even build. I get errors like

Answer 1

Got same issue on Xcode 11.2. Found out that the reason was that somewhere in same module I declared protocol State {}. This breaks compiler without any reasonable errors.