Unable to enforce default_language_version to enforce python_venv

[ssbarnea]

I tried to use the documented default_language_version override feature in order to enforce use of python3 + venv for creation of all virtualenvs but apparently this does not work as one would expect.

default_language_version:
  # avoid use of virtualenv which recently become unstable
  python: python_venv

https://github.com/pre-commit/pre-commit/search?q=python_venv&unscoped_q=python_venv

Is there a way to enforce this without having to touch each hook? In some repositories there lots of hooks defined.

Background

It seems that newer virtualenv releases stated to become more unstable, example pypa/virtualenv#1740

[asottile]

default_language_version is for overriding language_version, not language so I'm not sure why you expected that :)

if you're worried about the stability of virtualenv 20.x I'd suggest virtualenv<20 in your requirements -- that said, virtualenv 20.x has a setting to use venv, so that's probably a better option

[asottile]

note also, language: python_venv will be going away soon/eventually as virtualenv is now making venv-style environments

[ssbarnea]

So basically, by capping virtualenv version when I install, pre-commit I avoid being affected by this issue. Thanks, lucky me I am using tox, so very easy.

I do not mind seeing python_venv feature being dropped, I suppose use of venv would become the norm, right?

[asottile]

the other way, use of virtualenv would return to the only way now that it creates environments identical to venv

[gaborbernat]

That error makes no sense if you're actually using virtualenv 20.0.10 🤔