Swift Package Manager tools version for development snapshots

Question

I try to experiment with some of the new features of SPM that are recently implemented in swift 5.3. Like new binary dependencies and resources support. To test these new feature I went to swift.org and downloaded latest swift 5.3 development snapshot which is currently April 21, 2020. I installed it and selected as default toolchain in xcode preferences. However when I create new package with xcode it says swift-tools-version is 5.2. I tried to set it 5.3 like this // swift-tools-version:5.3. But xcode says

package at ... is using Swift tools version 5.3.0 but the installed version is 5.2.0

So my question is how can i test latest developments for spm from development snapshots?

Answer 1

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.

Answer 2

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.