swift-evolution/proposals/0450-swiftpm-package-traits.md at main · swiftlang/swift-evolution

Discover how traits act as feature flags, enabling conditional compilation, optional dependencies, and advanced package configurations.

Here's a place to start if you are trying to get a handle on Swift compiler settings.

The foundation of a Swift package is worth understanding.

At long last, package traits are now supported in Xcode and I think it's a big deal.