SwiftPM で swift-build を使う場合向けのドキュメントが作られそうです．現時点での known issues とかがまとめてあって参考になりますね． https://github.com/swiftlang/swift-package-manager/pull/9595

As the Swift Build integration reaching maturity, we are updating our documentation to better reflect the current state. Issue: rdar://167731860