Python 3.4 incompability: SyntaxError: can use starred expression only as assignment target

[Frode Nordahl]

ERROR juju-log Hook error:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/__init__.py", line 71, in main
    bus.discover()
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/bus.py", line 424, in discover
    _register_handlers_from_file(search_path, filepath)
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/bus.py", line 454, in _register_handlers_from_file
    _load_module(root, filepath)
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/bus.py", line 442, in _load_module
    return importlib.import_module(package + module)
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/importlib/__init__.py", line 109, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 2254, in _gcd_import
  File "<frozen importlib._bootstrap>", line 2237, in _find_and_load
  File "<frozen importlib._bootstrap>", line 2226, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1129, in _exec
  File "<frozen importlib._bootstrap>", line 1471, in exec_module
  File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
  File "/var/lib/juju/agents/unit-designate-2/charm/reactive/designate_handlers.py", line 17, in <module>
    import charm.openstack.designate as designate
  File "lib/charm/openstack/designate.py", line 25, in <module>
    import charms_openstack.plugins as ch_plugins
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms_openstack/plugins/__init__.py", line 19, in <module>
    from charms_openstack.plugins.classes import (
  File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms_openstack/plugins/classes.py", line 301
    *keyring_path_components,
                   ^
SyntaxError: can use starred expression only as assignment target

2020-06-15 16:07:20 DEBUG install Traceback (most recent call last):
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/charm/hooks/install", line 22, in <module>
2020-06-15 16:07:20 DEBUG install main()
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/__init__.py", line 71, in main
2020-06-15 16:07:20 DEBUG install bus.discover()
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/bus.py", line 424, in discover
2020-06-15 16:07:20 DEBUG install _register_handlers_from_file(search_path, filepath)
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/bus.py", line 454, in _register_handlers_from_file
2020-06-15 16:07:20 DEBUG install _load_module(root, filepath)
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms/reactive/bus.py", line 442, in _load_module
2020-06-15 16:07:20 DEBUG install return importlib.import_module(package + module)
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/importlib/__init__.py", line 109, in import_module
2020-06-15 16:07:20 DEBUG install return _bootstrap._gcd_import(name[level:], package, level)
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 2254, in _gcd_import
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 2237, in _find_and_load
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 2226, in _find_and_load_unlocked
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 1200, in _load_unlocked
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 1129, in _exec
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 1471, in exec_module
2020-06-15 16:07:20 DEBUG install File "<frozen importlib._bootstrap>", line 321, in _call_with_frames_removed
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/charm/reactive/designate_handlers.py", line 17, in <module>
2020-06-15 16:07:20 DEBUG install import charm.openstack.designate as designate
2020-06-15 16:07:20 DEBUG install File "lib/charm/openstack/designate.py", line 25, in <module>
2020-06-15 16:07:20 DEBUG install import charms_openstack.plugins as ch_plugins
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms_openstack/plugins/__init__.py", line 19, in <module>
2020-06-15 16:07:20 DEBUG install from charms_openstack.plugins.classes import (
2020-06-15 16:07:20 DEBUG install File "/var/lib/juju/agents/unit-designate-2/.venv/lib/python3.4/site-packages/charms_openstack/plugins/classes.py", line 301
2020-06-15 16:07:20 DEBUG install *keyring_path_components,
2020-06-15 16:07:20 DEBUG install ^
2020-06-15 16:07:20 DEBUG install SyntaxError: can use starred expression only as assignment target
2020-06-15 16:07:20 ERROR juju.worker.uniter.operation runhook.go:132 hook "install" failed: exit status 1

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/735790

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/735790
Committed: https://git.openstack.org/cgit/openstack/charms.openstack/commit/?id=d0431be73dd39f5b0ff0d90b1605c54757319ab0
Submitter: Zuul
Branch: master

commit d0431be73dd39f5b0ff0d90b1605c54757319ab0
Author: Frode Nordahl <email address hidden>
Date: Tue Jun 16 09:17:19 2020 +0200

    Drop use of tuple unpacking to fix Python 3.4 compability

    Use of Tuple unpacking in function arguments was not completely
    generalized until PEP-448 [0] was implemented in Python 3.5.

    Revert to using List instead until we the old snakes have retired.

    0: https://www.python.org/dev/peps/pep-0448/

    Change-Id: I4befe75d3a9f976bb32f49895833562bcf822c9c
    Closes-Bug: #1883657