We're running Core's PHP unit tests against the GB plugin in our CI environment (on WordPress.com). When installing GB 9.2.1, one of those tests errored because of an issue. (A fix is underway.) That issue wasn't caught in Gutenberg's own tests, since we're not running Core's unit tests.

To catch these issues prior to a release, I propose we run Core's unit tests against GB inside of this repo -- e.g. as part of the unit tests GitHub action, so that it's run on every PR, and informs the author of any errors.

cc/ @sirreal @WunderBart @fullofcaffeine @nosolosw @gziolo