ansible/test/integration/targets/conditionals/test_warnings.yml

- hosts: testhost
  gather_facts: false
  vars:
    str_boolean_var: 'false'
  tasks:
  - name: Run tasks with warnings for conditionals that will change in behavior depending on CONDITIONAL_BARE_VARS
    block:
    - debug:
      when: str_boolean_var
    - debug:
      when: double_interpolated
      vars:
        double_interpolated: other
        other: false