This package provides an example of a Swift Package Manager package with mixed language sources.
Building or testing this package is not currently supported in Xcode or with
an official release of Swift Package Manager. Instead, checkout
swiftlang/swift-package-manager#5919 and follow the
instructions here
to get the local version of SPM building. Then, select the swift-test scheme,
and edit it to add the --package-path /path/to/MixedPackage argument. This will
set MixedPackage as the package to build and test.
From there, the package should build successfully and all tests should pass. Please open an issue if you run into any trouble.