Add missing unit test for https://github.com/apple/swift-package-manager/pull/2891 (#3140)
Add missing unit test for https://github.com/apple/swift-package-manager/pull/2891 (#3140)

We merged that PR without a unit test, this adds one.

rdar://68158441
abertelrud/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager