ios - xcodebuild and swift package manager, can't resolve package graphs - Stack Overflow

TLDR: how can I get Resolve Package Graphs to succeed when running Xcode 16 under Fastlane? Is there some option to scan I am missing or some setup/config I need to do prior to running scan?

My company is using Fastlane to run tests when we open PR's. It's failing while trying to resolve package graphs for SPM / Swift Package Manager packages.

With Xcode 15, this runs great:

    desc """
        Builds a Debug configuration of the app and runs its tests.
        - Example usage: `fastlane test`
    """
    lane :test do
        puts(message: "about to scan for tests ☺️")
        scan(
            workspace: "MyWonderfulApp.xcworkspace",
            scheme: "MyWonderfulApp",
            configuration: "Debug",
            cloned_source_packages_path: "~/SourcePackages",
            clean: true,
            reset_simulator: true,
            device: "iPhone 15" - or "iPhone 16" if we're under Xcode 16
        )
        puts(message: "done scanning for tests")
    end

And the log looks something like this:

[16:29:47]: Driving the lane 'ios test'