lookup plugin (task_src), again?

Hi, I use debops for quite some time now and recently updated to ansible 2.10.5.  I got the  : /lookup plugin (task_src)fatal: [sentry_server]: FAILED! => {"msg": "lookup plugin (task_src) not found"}/ in the past and solved it by adding the lookup_plugins to my "playbooks" dir. But today it keep complaining about it for plays that use role:users  and role: resources. I tried to symlink it in different places that appear in the ansible.cfg but it doesn't help. I created a clean virtualenv and installed debops with : pip install debops[ansible], but the result is the same, so the error should be on my side... Does anybody see something that I could have done wrong or forgot to update? Best regards PHiL