- when: lookup('pipe', ansible_playbook_python ~ ' -c "import jinja2; print(jinja2.__version__)"') is version('2.7', '>=') block: - set_fact: names: '{{ things|map(attribute="name") }}' vars: things: - name: one - name: two - notname: three - name: four - assert: that: - '"%r"|format(undef) == "AnsibleUndefined"' # The existence of AnsibleUndefined in a templating result # prevents safe_eval from turning the value into a python object - names is string - '", AnsibleUndefined," in names'