- hosts: localhost gather_facts: false tasks: - name: does nothing but an empty assign, should fail only if lookup gets invalid options set_fact: whatever={{ lookup('bogus', 1, test_list=['Dan', 'Manuela']) }} - name: now pass invalid option and fail! set_fact: whatever={{ lookup('bogus', 1, test_list=['Dan', 'Manuela', 'Yoko']) }} register: bad_input ignore_errors: true - name: ensure it fails as expected assert: that: - bad_input is failed - '"Invalid value " in bad_input.msg' - '"valid values are:" in bad_input.msg'