This is my babel.cfg file:
[python: **.py]
[jinja2: **/templates/**.html]
When I execute this command:
pybabel extract -F babel.cfg -k _l -o messages.pot .
Then return this error:
ValueError: Unknown extraction method 'jinja2'
¿How is it possible? That example of config is literally gotten from docs

Surprisingly:
sudo pip install --upgrade setuptools
Updating the setuptools on my mac and now it works...