Fails to work under mitogen

[gilesw]

- name: create pg_trgm and ltree extension for indexing like queries
  postgresql_exec:
    content: "{{ item }}"
    db: "wibble"
    login_host: "localhost"
    login_user: "wibble"
    login_password: "wibble"
  with_items:
    - "create extension if not exists pg_trgm"
    - "create extension if not exists ltree"
  ignore_errors: true
  run_once: true
  changed_when: False

2019-02-28 15:43:26,087 p=21097 u=gilesadm |  ERROR! [pid 21115] 15:43:26.087054 I mitogen.ctx.ssh.xxxx: stderr:     self._return_formatted(kwargs)
2019-02-28 15:43:26,152 p=21097 u=gilesadm |  ERROR! [pid 21115] 15:43:26.152651 I mitogen.ctx.ssh.xxxx: stderr:   File "master:/opt/python-tools/lib/python2.7/site-packages/ansible/module_utils/basic.py", line 2342, in _return_formatted
2019-02-28 15:43:26,153 p=21097 u=gilesadm |  ERROR! [pid 21115] 15:43:26.152955 I mitogen.ctx.ssh.xxxx: stderr:     print('\n%s' % self.jsonify(kwargs))
2019-02-28 15:43:26,153 p=21097 u=gilesadm |  ERROR! [pid 21115] 15:43:26.153250 I mitogen.ctx.ssh.cspbwbluclprt160x1.ext.dyn.semcs.net: stderr: ValueError: I/O operation on closed file
2019-02-28 15:43:26,153 p=21097 u=gilesadm |  [pid 21115] 15:43:26.153545 D mitogen.ctx.ssh.xxxx: mitogen: _dispatch_calls: Message(1004, 2009, 0, 101, 1003, '\x80\x02(U,devgiles01c-21356-7fb50a767700-582f626abf77eq'..1747) -> CallError(u'exceptions.AttributeError: \'file\' object has no attribute \'getvalue\'\n  File "<stdin>", line 3078, in _dispatch_one\n  File "master:/home.local/gilesadm/work/ansible-config/mitogen-0.2.5/ansible_mitogen/target.py", line 430, in run_module\n    return impl.run()\n  File "master:/home.local/gilesadm/work/ansible-config/mitogen-0.2.5/ansible_mitogen/runner.py", line 382, in run\n    return self._run()\n  File "master:/home.local/gilesadm/work/ansible-config/mitogen-0.2.5/ansible_mitogen/runner.py", line 887, in _run\n    u\'stdout\': mitogen.core.to_text(sys.stdout.getvalue()),\n',)

runs fine on standard with output:-

ok: [xxxx] => (item=create extension if not exists ltree) => {"changed": false, "item": "create extension if not exists ltree", "rowcount": -1, "rowfirst": null, "rows": null, "statusmessage": "CREATE EXTENSION"}