Sorry, title should be Xcode 13, cannot edit this anymore

Hi, 

I am using purchases-ios via Swift Package Manager with the latest version 3.12.4. After downloading Xcode 13 my app builds and runs both on device and simulator.

When I try to archive the app in order to upload it to the App Store, I receive the following message:

Command CompileSwiftSources failed with a nonzero exit code.

The line before says

remark: Incremental compilation has been disabled: it is not compatible with whole module optimization

There is no other message before or after which gives an indication of what the error could be.

The minimum target is iOS 13.

I tried to clean the build folder, restart Xcode, restart the Mac, downloaded the project manually from the repository and set it up newly, nothing worked.

I am clueless, what can be the problem here?