- hosts: localhost
  tasks:
    - command: whoami
      register: whoami

    - assert:
        that:
          - whoami is successful

    - set_fact:
        me: "{{ whoami.stdout }}"

- hosts: localhost
  user: "{{ me }}"
  tasks:
    - debug:
        msg: worked with user ({{ me }})

- hosts: localhost
  remote_user: "{{ me }}"
  tasks:
    - debug:
        msg: worked with remote_user ({{ me }})