Adding --debug breaks argument parsing

This is on 22.04.3, specifically 23.3.1-0ubuntu1~22.04.1

I'm planning to use "cloud-init clean" to prepare golden images. I was hoping to get some insight into what, exactly, the script is doing under the hood (reading cmd/clean.py helps but part of that is hard to follow without already knowing the internals of cloud-init) so I tried running with the '--debug' flag documented as showing "additional pre-action logging".

% cloud-init --debug clean -h
usage: /usr/bin/cloud-init clean [-h]

options:
  -h, --help show this help message and exit

Interesting, but removing --debug helps:

% cloud-init clean -h
usage: /usr/bin/cloud-init clean [-h] [-l] [--machine-id] [-r] [-s]

options:
  -h, --help show this help message and exit
  -l, --logs Remove cloud-init logs.
  --machine-id Set /etc/machine-id to [...elided for launchpad brevity...]
  -r, --reboot Reboot system after logs are cleaned so cloud-init re-runs.
  -s, --seed Remove cloud-init seed directory /var/lib/cloud/seed.

Okay, in fairness, most users won't be running --debug at the same time as --help, but I would still have expected it to print *at least* the same help output if not more debugging stuff.

So I try running it for realsies:

# cloud-init --debug clean --logs --machine-id --seed
usage: /usr/bin/cloud-init [-h] [--version] [--file FILES] [--debug] [--force]
                           {init,modules,single,query,features,analyze,devel,collect-logs,clean,status,schema} ...
/usr/bin/cloud-init: error: unrecognized arguments: --logs --machine-id --seed

# cloud-init --debug clean
Traceback (most recent call last):
  File "/usr/bin/cloud-init", line 33, in <module>
    sys.exit(load_entry_point('cloud-init==23.3.1', 'console_scripts', 'cloud-init')())
  File "/usr/lib/python3/dist-packages/cloudinit/cmd/main.py", line 1036, in main
    (name, functor) = args.action
AttributeError: 'Namespace' object has no attribute 'action'

That outcome is less than awesome.

Running without --debug worked:

# cloud-init clean --logs --machine-id --seed
# echo $?
0
#

Although in the absence of --debug output, it's necessary to go look around the filesystem to verify what's been changed vis-a-vis what options were given.