This is a test package which uses the Infomatic plugin to embed a version number into the executable in a way that's accessible at runtime.
Xcode currently seems to have trouble running this plugin, but it works fine from the command line. Just do:
swift run
to build & run this executable.
Doing so should fetch, build & run the plugin as part of the build process.
See https://github.com/elegantchaos/InfomaticPlugin for the plugin itself.