This and my ReproLibrary combine to expose a bug in the Polylith tool.
It should be possible to run poly test in this repo, but the polylith tool (as of August 10, 2021) instead reports a long error, ultimately about how it has two versions of the "repro-lib/root" library. It does this even though that library, which is a transitive dependency of two libraries this repo does use, is correctly excluded.
Note that Kaocha can be used to run the tests, through the script kaocha.sh.