Cannot pickle '_io.TextIOWrapper' object

I have an older project (Trellis 1.1.0 + Bedrock 1.12.8) now enabled to run with Trellis CLI (trellis init in project root with Trellis CLI 1.7.0 installed on macOS).

trellis up appears to run as expected, but the local site does not load.

trellis provision development results in the following:

- composer (1.7.6) is already installed, skipping.
- ntp (1.6.4) is already installed, skipping.
- logrotate (v0.0.5) is already installed, skipping.
- swapfile (v2.0.22) is already installed, skipping.
- mailhog (2.1.4) is already installed, skipping.

Running command => ansible-playbook dev.yml -e env=development --inventory-file .vagrant/provisioners/ansible/inventory/vagrant_ansible_inventory
 [WARNING]: Skipping plugin (/Users/ ... /trellis/.trellis/virtualenv/lib/python3.9/site-packages/ansible/plugins/filter/core.py) as it seems to be
invalid: cannot import name 'environmentfilter' from 'jinja2.filters' (/Users/ ... /trellis/.trellis/virtualenv/lib/python3.9/site-packages/jinja2/filters.py)


PLAY [Set ansible_python_interpreter] **************************************************************************
 [WARNING]: You Ansible version is 2.7.18 but this version of Trellis has only been tested for compatability
with Ansible 2.7.12 -> 2.7.13. It is advisable to check for Trellis updates or downgrade your Ansible version.


TASK [python_interpreter : Get Ubuntu release] *****************************************************************
ERROR! Unexpected Exception, this is probably a bug: cannot pickle '_io.TextIOWrapper' object
to see the full traceback, use -vvv
exit status 250

I reran trellis init in the project root as advised elsewhere, but no change.

Questions: Where do I find information about what should be installed (given the Trellis version in use here) vs what is, how/where to vvv, etc?

Bigger questions: Shouldn’t trellis init have taken care of all requirements? What could have changed in this setup (I believe it did indeed run successfully since trellis initing for the first time some weeks ago), and I have not cherry-picked any Trellis updates?