-m setup -a filter="ansible_eth0.ipv4.address" returns no results

Yes, it will then rerun facts after facter is installed so you will get facters fact in the current run.

If gather_facts is true, you will run gather facts two time every time you run the play.
If this is not desired you could also do it like this

- name: install facter
   yum:
     name: facter
     state: latest
   register: installed_facter

- setup:
   when: installed_facter | changed

Thanks Kai, that did the trick.

Unrelated to this thread, I really need some help with this other problem I’m having: https://groups.google.com/d/topic/ansible-project/IuZPsZ4CBS8/discussion so if any of the helpful souls in this thread can have a look, I’d appreciate it.