I made a widget using new and shiny WidgetKit. It looks good and working as expected. Then I put all its logic into separate framework to share constant values between extension and main app as well as to provide a unit-testable target. And after introducing a framework SwiftUI previews stopped working. I'm getting error: Cannot preview in this file - Could not find host for previews. It seems that WidgetPreviewContext is not working. I'm wondering why. Could it be because I'm on macOS Catalina 10.15.6?