Ansible-lint pre-commit problem + “fix”¶

Tags: python, django

I’m used to running pre-commit autoupdate regularly to update the versions of the linters/formatters that I use. Especially when there’s some error.

For example, a couple of months ago, there was some problem with ansible-lint. You have an ansible-lint, ansible and ansible-core package and one of them needed an upgrade. I’d get an error like this:

ModuleNotFoundError: No module named 'ansible.parsing.yaml.constructor'

The solution: pre-commit autoupdate, which grabbed a new ansible-lint version that solved the problem. Upgrading is good.

But… little over a month ago, ansible-lint pinned python to 3.13 in the pre-commit hook. So when you update, you suddenly need to have 3.13 on your machine. I have that locally, but on the often-used “ubuntu latest” (24.04) github action runner, only 3.12 is installed by default. Then you’d get this:

[INFO] Installing environment for https://github.com/pre-commit/pre-commit-hooks.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/astral-sh/ruff-pre-commit.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/ansible-community/ansible-lint.git.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
An unexpected error has occurred: CalledProcessError: command:
  ('/opt/hostedtoolcache/Python/3.12.12/x64/bin/python', '-mvirtualenv',
  '/home/runner/.cache/pre-commit/repomm4m0yuo/py_env-python3.13', '-p', 'python3.13')
return code: 1
stdout:
    RuntimeError: failed to find interpreter for Builtin discover of python_spec='python3.13'
stderr: (none)
Check the log at /home/runner/.cache/pre-commit/pre-commit.log
Error: Process completed with exit code 3.

Ansible-lint’s pre-commit hook needs 3.10+ or so, but won’t accept anything except 3.13. Here’s the change: https://github.com/ansible/ansible-lint/pull/4796 (including some comments that it is not ideal, including the github action problem).

The change apparently gives a good error message to people running too-old python versions, but it punishes those that do regular updates (and have perfectly fine non-3.13 python versions). A similar pin was done in “black” and later reverted (see the comments on this issue) as it caused too many problems.

Note: this comment gives some of the reasons for hardcoding 3.13. Pre-commit itself doesn’t have a way to specify a minimum Python version. Apparently old Python version cans lead to weird install errors, though I haven’t found a good ticket about that in the issue tracker. The number of issues in the tracker is impressively high, so I can imagine such a hardcoded version helping a bit.

Now on to the “fix”. Override the language_version like this:

- repo: https://github.com/ansible-community/ansible-lint.git
  hooks:
    - id: ansible-lint
      language_version: python3  # or python3.12 or so

If you use ansible-lint a lot (like I do), you’ll have to add that line to all your (django) project repositories when you update your pre-commit config…

I personally think this pinning is a bad idea. After some discussion in issue 4821 I created a sub-optimal proposal to at least setting the default to 3.12, but that issue was closed&locked because I apparently “didn’t search the issue tracker”.

Anyway, this blog post hopefully helps people adjust their many pre-commit configs.