Unknown parameter $deriver in Attributes

Aha good point, I should have checked Drupal core plugins.

Is it enough to just add this property to the attribute classes? Or do we have to do anything on the plugin managers as well? Probably not, as you say the property is defined on the parent Plugin attribute class.

This should do it, please test!

Merged that one already, let me know if you still see a problem!

Sorry, timezones, was asleep! 2 quick :D
Yes thats working as expected now