ansible/test/integration/targets/includes_race/test_includes_race.yml

- hosts: all
  strategy: free
  gather_facts: false
  tasks:
    - include_role:
        name: random_sleep
    - block:
      - name: set a fact (1)
        include_role:
          name: set_a_fact
          tasks_from: fact1.yml
      - name: set a fact (2)
        include_role:
          name: set_a_fact
          tasks_from: fact2.yml
    - name: include didn't run
      fail:
        msg: "set_a_fact didn't run fact1 {{ fact1 | default('not defined')}} fact2: {{ fact2 | default('not defined') }}"
      when: (fact1 is not defined or fact2 is not defined)