Plotting a Path to a Package Ecosystem without Data Race Errors

Swift 6 introduces compile-time data race safety checking for any code that opts in to use the Swift 6 language mode. While individual modules can adopt this mode incrementally and independently of their dependencies, the full benefit of runtime data race safety is only realized when all modules have opted in. Therefore, the quick adoption of Swift 6 language mode across the ecosystem of open-source packages will play a key role in advancing data race safety across the entire Swift ecosystem.

→ swift.org/blog/ready-for-swift-6/

Swift 6 introduces compile-time data race safety checks for code opting into the Swift 6 language mode, significantly reducing crashes and performance issues, but full benefits require ecosystem-wide adoption.

The Swift Package Index’s “Ready for Swift 6” page tracks package compatibility, showing over 43% of packages compile without data race errors using nightly toolchains, with progress driven by package authors fixing issues and compiler refinements.

Packages free of data race errors display a “Safe from data races” label, though some may be Swift 6-compatible without strict checks enabled. The SSWG encourages developers to adopt the Swift 6 language mode in their packages to enhance safety and maintainability, contributing to a community-wide transition, with progress trackable on the Swift Package Index.