How can I see which commands ansible runs and their output?

I'm new to Ansible, and yes I know this has already been asked many times, but I already tried to apply advice I saw elsewhere.

I did export ANSIBLE_STDOUT_CALLBACK=debug and then ansible-playbook -vvvvvv arch-upgrade.yaml -l my-host with arch-upgrade.yaml below:

- name: ArchLinux up-to-date
  hosts: all
  tasks:
    - name: full system upgrade
      pacman:
        update_cache: yes
        upgrade: yes
      register: out
    - debug: msg="{{ out }}"

I get a lot of details about how ansible opens it's ssh connections, transfers its python file, runs it remotely, etc. but as far as I can tell, not a single thing about what command the python script actually ran and what it returned (stdout, stderr, return code). That's why I'm not including this very long log here, but I can upon request.

Is someone aware of how I can ask ansible to be more verbose about what it does (and not how it does it) ?