- hosts: localhost
  gather_facts: false
  tasks:
    - name: skipped include undefined loop
      ansible.builtin.include_tasks: doesnt_matter.yml
      loop: '{{ lkjsdflkjsdlfkjsdlfkjsdf }}'
      when: false
      register: skipped_include

    - debug:
        var: skipped_include

    - assert:
        that:
          - skipped_include.results is undefined
          - skipped_include.skip_reason is defined
          - skipped_include is skipped