Error with paternoster, runs with ansible-playbook

[jrast]

I have the following very simple tasks:

#!/usr/bin/env paternoster

- hosts: paternoster
  vars:
    description: Mount a WebDav Filesystem
    parameters:
      - name: target
        help: "Target Directory / Mount Point"
        required: yes
        type: paternoster.types.restricted_str
        type_params:
          regex: "^/media/[a-zA-Z0-9_-]+$"

- hosts: localhost
  tasks:
    - debug: msg="Installing WebDavFS..."

    - name: Installing WebDavFS
      become: true
      ansible.builtin.apt:
        name: davfs2
        state: present
        update_cache: yes
        cache_valid_time: 86400

    - debug: msg="Creating Mountpoint {{ param_target}}"

If I run them with ansible-playbook ( ansible-playbook MountWebDav --extra-vars "param_target=/media/sharepoint" > ansible-run.log), this works as expected, however, if I run the script with paternoster MountWebDav I get an AttributeError:

Parsed localhost, inventory source with host_list plugin
Skipping callback 'default', as we already have a stdout callback.
Skipping callback 'minimal', as we already have a stdout callback.
Skipping callback 'oneline', as we already have a stdout callback.

PLAYBOOK: MountWebDav **********************************************************
2 plays in /home/pi/Desktop/AnsibleScripts/MountWebDav

PLAY [paternoster] *************************************************************
skipping: no hosts matched

PLAY [localhost] ***************************************************************

TASK [Gathering Facts] *********************************************************
task path: /home/pi/Desktop/AnsibleScripts/MountWebDav:14
<localhost> ESTABLISH LOCAL CONNECTION FOR USER: pi
<localhost> EXEC /bin/sh -c '( umask 77 && mkdir -p "` echo /tmp `"&& mkdir "` echo /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048 `" && echo ansible-tmp-1618295847.6610847-20529-101535705936048="` echo /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048 `" ) && sleep 0'
Using module file /home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/modules/setup.py
<localhost> PUT /tmp/ansible-local-20516ye305jqp/tmpt53z4k14 TO /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048/AnsiballZ_setup.py
<localhost> EXEC /bin/sh -c 'chmod u+x /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048/ /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048/AnsiballZ_setup.py && sleep 0'
<localhost> EXEC /bin/sh -c '/home/pi/Desktop/AnsibleScripts/venv/bin/python3 /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048/AnsiballZ_setup.py && sleep 0'
<localhost> EXEC /bin/sh -c 'rm -f -r /tmp/ansible-tmp-1618295847.6610847-20529-101535705936048/ > /dev/null 2>&1 && sleep 0'
ok: [localhost]
META: ran handlers

TASK [debug] *******************************************************************
task path: /home/pi/Desktop/AnsibleScripts/MountWebDav:16
ok: [localhost] => {
    "msg": "Installing WebDavFS..."
}

TASK [Installing WebDavFS] *****************************************************
task path: /home/pi/Desktop/AnsibleScripts/MountWebDav:18
The full traceback is:
Traceback (most recent call last):
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/executor/task_executor.py", line 158, in run
    res = self._execute()
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/executor/task_executor.py", line 613, in _execute
    self._connection = self._get_connection(cvars, templar)
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/executor/task_executor.py", line 929, in _get_connection
    become_plugin = self._get_become(self._task.become_method)
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/executor/task_executor.py", line 883, in _get_become
    become = become_loader.get(name)
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/plugins/loader.py", line 782, in get
    return self.get_with_context(name, *args, **kwargs).object
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/plugins/loader.py", line 792, in get_with_context
    plugin_load_context = self.find_plugin_with_context(name, collection_list=collection_list)
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/plugins/loader.py", line 541, in find_plugin_with_context
    result = self._resolve_plugin_step(name, mod_type, ignore_deprecated, check_aliases, collection_list, plugin_load_context=plugin_load_context)
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/plugins/loader.py", line 632, in _resolve_plugin_step
    return self._find_plugin_legacy(name, plugin_load_context, ignore_deprecated, check_aliases, suffix)
  File "/home/pi/Desktop/AnsibleScripts/venv/lib/python3.7/site-packages/ansible/plugins/loader.py", line 714, in _find_plugin_legacy
    if not name.startswith('_'):
AttributeError: 'NoneType' object has no attribute 'startswith'
fatal: [localhost]: FAILED! => {
    "msg": "Unexpected failure during module execution.",
    "stdout": ""
}

PLAY RECAP *********************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0  

Versions:
Python: 3.7.2
Ansible: 2.10.7
Paternoster: 3.2.1

[luto]

Which distribution is this running on? Ubuntu?

[jrast]

I'm running this on a Raspberry Pi with Raspbian 10, which is almost the same as a Debian 10 (buster).

Ansible and Paternoster are installed within a virtual environment, maybe this also leads to some issues?