Swift 6.4 makes Swift Build the default engine for Swift Package Manager, unifying dependency management, compilation, linking and testing. This matters because developers can now follow the same build process across Linux, macOS and Windows, using Xcode, the command line or VS Code, potentially making cross-platform development faster and more consistent.

Swift Build automatically installs and checks dependencies before producing CPU-specific binaries, while a new tool generates Software Bills of Materials in SPDX or CycloneDX formats for auditing. Swift Package Index, acquired by Apple in June, hosts more than 10,400 packages, and the release also improves LLDB’s storage efficiency and interoperability with C++, Java, JavaScript and WebAssembly.