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##### SUMMARY
When enabling zuul's executor verbose status for ansible, there are a lot of traces like:
```
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'(<ansible.plugins.callback.zuul_unreachable.CallbackModule object at'
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b"0x7f0d248e2c10>): 'show_per_host_start'"
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'Callback Exception:'
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'  File "/usr/local/lib/zuul/ansible/2.9/lib/python3.7/site-packages/ansible/executor/task_queue_manager.py", line 324, in send_callback'
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'    method(*new_args, **kwargs)'
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'   File "/usr/local/lib/zuul/ansible/2.9/lib/python3.7/site-packages/ansible/plugins/callback/default.py", line 256, in v2_runner_on_start'
2020-06-08 17:33:29,930 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b"    if self.get_option('show_per_host_start'):"
2020-06-08 17:33:29,931 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'   File "/usr/local/lib/zuul/ansible/2.9/lib/python3.7/site-packages/ansible/plugins/callback/__init__.py", line 91, in get_option'
2020-06-08 17:33:29,931 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'    return self._plugin_options[k]'
2020-06-08 17:33:30,126 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'Using module file /usr/local/lib/zuul/ansible/2.9/lib/python3.7/site-packages/ansible/modules/system/setup.py'
2020-06-08 17:33:30,126 DEBUG zuul.AnsibleJob.output: [e: 26a6cd8eb86144b9871b4841690cca62] [build: 71bc75c1ccc448aaa064ae393fe6ae51] Ansible output: b'Pipelining is enabled.'
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
!component 

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.9.9
  config file = None
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/zuul/ansible/2.9/lib/python3.7/site-packages/ansible
  executable location = /usr/local/lib/zuul/ansible/2.9/bin/ansible
  python version = 3.7.7 (default, Apr 23 2020, 14:54:40) [GCC 8.3.0]

```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
config per playbooks used by zuul is defined in https://opendev.org/zuul/zuul/src/branch/master/zuul/executor/server.py#L2019-L2109
no show_per_host_start config is written, but ansible source shows that a default value should be defined, see "EXPECTED RESULTS" below

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
docker image zuul/zuul-executor image:7e5160e0f9b0

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
run zuul quick-start tutorial https://zuul-ci.org/docs/zuul/tutorials/quick-start.html
enable executor debug logging:
add `doc/source/examples/etc_zuul/logging.conf` 
```
[loggers]
keys=root,zuul

[handlers]
keys=console

[formatters]
keys=simple

[logger_root]
level=INFO
handlers=console

[logger_zuul]
level=DEBUG
handlers=console
qualname=zuul
propagate=0

[handler_console]
level=DEBUG
class=StreamHandler
formatter=simple
args=(sys.stdout,)

[formatter_simple]
format=%(asctime)s %(levelname)s %(name)s: %(message)s
datefmt=

```
in `doc/source/examples/etc_zuul/zuul.conf` add `log_config=/etc/zuul/logging.conf` to `[executor]`

perform steps manually or using
`ansible-playbook -v playbooks/quick-start/localtest.yaml`
when executor container is up and executor is available, run:
`docker exec examples_executor_1 zuul-executor verbose`

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
default value defined in https://github.com/ansible/ansible/blob/devel/lib/ansible/plugins/callback/default.py#L56-L60
and/or https://github.com/ansible/ansible/blob/devel/lib/ansible/config/base.yml updated to include default value

as described in https://github.com/ansible/ansible/blob/devel/lib/ansible/plugins/doc_fragments/default_callback.py#L58-L68


##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below

```

delegated_vars = result._result.get('_ansible_delegated_vars', None)
        if isinstance(result._task, TaskInclude):
            return
        elif result._result.get('changed', False):
            if self._last_task_banner != result._task._uuid:
                self._print_task_banner(result._task)
            msg = 'changed'
            color = C.COLOR_CHANGED
        else:
            if not self.display_ok_hosts:
                return
            if self._last_task_banner != result._task._uuid:
                self._print_task_banner(result._task)
            msg = 'ok'
            color = C.COLOR_OK
        if delegated_vars:
            msg += ": [%s -> %s]" % (result._host.get_name(), delegated_vars['ansible_host'])
        else:
            msg += ": [%s]" % result._host.get_name()
        msg += " => (item=%s)" % (self._get_item_label(result._result),)
        self._clean_results(result._result, result._task.action)
        if self._run_is_verbose(result):
            msg += " => %s" % self._dump_results(result._result)
        self._display.display(msg, color=color)
    def v2_runner_item_on_failed(self, result):