Running just vendor/bin/phpunit will run both the unit and the compat test suites, which is expected behaviour.

The unit test suite covers the library unit implementation. The unit tests can be executed by simply running (--colors is optional):

These are the unmodified core reflection .phpt tests that verify functionality of the core reflection API. They are provided only for information/comparison purposes and can be run simply like this:

These are adapted versions of the core reflection .phpt tests that have been modified to use Better Reflection instead of core reflection. The idea is that we are trying to maintain compatibility with core API. Ideally, these should pass (where they pass in core, at least).