Swift Package Manager tools version for development snapshots

In Package.swift

// swift-tools-version:5.3

Although it's a comment and it should be ignored, it's not! change it to :

// swift-tools-version:5.2

_{Sometimes you need to delete .build and .swiftpm directories (that are hiddent by default) too.}

Note

Don't forget to close and reopen the project after the changes.

swift xcode swift-package-manager

To use the new toolchain from the command line, you first need to export it:$ export TOOLCHAINS=swift.

Then you can check which version you use with: $ swift --version

See apple documentation on managing multiple swift environment and choosing a swift version here.