Is ansible-core-2.11.12 still supported by latest mitogen-0.3.9?

[iredmail]

Tried to upgrade ansible and mitogen to supported versions on Ubuntu 18.04 (Python 3.6.9), but the latest supported Ansible is 4.10.0 with ansible-core-2.11.12. Tried all mitogen-0.3.x, but all report error like below:

ERROR! Your Ansible version (2.11.12) is too recent. The most recent version
supported by Mitogen for Ansible is (2, 9).x.

According to mitogen changelog, ansible-core-2.11 should be supported since mitogen-0.3.1:
https://github.com/mitogen-hq/mitogen/blob/master/docs/changelog.rst#v031-unreleased

[moreati]

Works for me.

1. What is the absolute path to your MItogen 0.3.9 install?
2. In ansible.cfg what is the value of strategy_plugins? Or alternatively the environment variable ANSIBLE_STRATEGY_PLUGINS?

Using an Ubuntu 18.04 container on Proxmox

root@u1804:~# virtualenv -p python3 v36
...
root@u1804:~# v36/bin/pip install ansible ansible-core==2.11.12 mitogen
...
root@u1804:~# ANSIBLE_STRATEGY=mitogen_linear ANSIBLE_STRATEGY_PLUGINS=v36/lib/python3.6/site-packages/ansible_mitogen/plugins/strategy/ v36/bin/ansible localhost -mping
[DEPRECATION WARNING]: Ansible will require Python 3.8 or newer on the controller starting with Ansible 2.12. Current version: 3.6.9 (default, Mar 10 2023, 16:46:00) [GCC 8.4.0]. This feature will be removed from ansible-core in 
version 2.12. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
/root/v36/lib/python3.6/site-packages/ansible/parsing/vault/__init__.py:44: CryptographyDeprecationWarning: Python 3.6 is no longer supported by the Python core team. Therefore, support for it is deprecated in cryptography. The next release of cryptography will remove support for Python 3.6.
  from cryptography.exceptions import InvalidSignature
localhost | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

root@u1804:~# v36/bin/python --version; v36/bin/pip list
Python 3.6.9
Package       Version
------------- -------
ansible       4.10.0
ansible-core  2.11.12
cffi          1.15.1
cryptography  40.0.2
Jinja2        3.0.3
MarkupSafe    2.0.1
mitogen       0.3.9
packaging     21.3
pip           21.3.1
pkg_resources 0.0.0
pycparser     2.21
pyparsing     3.1.2
PyYAML        6.0.1
resolvelib    0.5.4
setuptools    59.6.0
wheel         0.37.1