Description of problem:
undercloud update fails, 
The log contains lots of Warnings like:

"Warning: The function 'hiera' is deprecated in favor of using 'lookup'. See https://puppet.com/docs/puppet/5.5/deprecated_language.html\\n   (file & line not available)"

"Warning: /etc/puppet/hiera.yaml: Use of 'hiera.yaml' version 3 is deprecated. It should be converted to version 5",

"Warning: Undefined variable '::deploy_config_name'; \\n   (file & line not available)",

"Warning: ModuleLoader: module 'openstacklib' has unresolved dependencies - it will only see those that are resolved. Use 'puppet module list --tree' to see information about modules\\n   (file & line not available)"


AND at the end, it fails with:

1. "Exception: Deployment failed
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/tripleoclient/v1/tripleo_deploy.py", line 1256, in _standalone_deploy
    raise exceptions.DeploymentError('Deployment failed')
tripleoclient.exceptions.DeploymentError: Deployment failed
None "

2."During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/tripleoclient/command.py", line 30, in run
    super(Command, self).run(parsed_args)
  File "/usr/lib/python3.6/site-packages/osc_lib/command/command.py", line 41, in run
    return super(Command, self).run(parsed_args)
  File "/usr/lib/python3.6/site-packages/cliff/command.py", line 184, in run
    return_code = self.take_action(parsed_args) or 0
  File "/usr/lib/python3.6/site-packages/tripleoclient/v1/undercloud.py", line 178, in take_action
    raise exceptions.DeploymentError(e)"

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1. install osp15
2. update python3-tripleoclient* openstack-tripleo-common openstack-tripleo-heat-templates
3. run openstack undercloud upgrade

Actual results:
update failed

Expected results:


Additional info: