Issue has been resolved since (I believe in Xcode 16).

The issue has been resolved since. In our case, it was SwiftUI views in packages imported for local development would not build. But they started building and behaving as expected in later versions of Xcode. Thanks!

Are you seeing this behavior with views located in your app or located in packages? Views in packages only. The scheme approach does not work for me; the scheme is always the one the view is located in, but it still doesn't work. My solution has been creating a "host" app, and previewing the package views in the app instead of from within the package.