Is it possible to test settings-plugins via 'testkit' in same repo?

Hi all!

I’m trying to test a settings-based plugin via “functional tests” (similar to what is described here Testing Gradle plugins ), but getting an error

    An exception occurred applying plugin request [id: 'xxx']
    > Failed to apply plugin 'xxx'.
       > The root project is not yet available for build.

Is it at all possible to test settings-plugins using GradleRunner (or something similar)?