Building on the thread above but a slightly different problem: I now have mypy 1.1.1 configured correctly. When I do

pants check my_file.py

mypy raises things that I expect - great! I now configured a pre-commit hook as such:

repos:

- repo: local

hooks:

- id: check

name: check

entry: pants check

language: system

files: ^.*.(py|pyi)$

When I now git add and git commit the same file mypy fails with this error:

.cache/pex_root/venvs/5cb0b2dcd2357da2bbde0d877bde9b817c555a3e/fde49d60105c0ef9833901ddf249f36d7deded9a/lib/python3.11/site-packages/numpy/__init__.pyi641 error: Positional-only parameters are only supported in Python 3.8 and greater

This problem comes from an old mypy version and should be already fixed (ref). I am puzzled where this discrepancy of different mypy version stems from and would be excited if someone could help me out here!

So you have configured the lockfile etc? Are you able to run successfully without the hook?

pants check ::

[mypy]

version = "mypy==1.1.1"

args = ["--non-interactive", "--install-types"]

extra_type_stubs = ["types-requests==2.25.12"]

# Set this to a path, then run

pants generate-lockfiles --resolve=mypy-extra-type-stubs

.

extra_type_stubs_lockfile = "3rdparty/python/mypy_extra_type_stubs.lock"

lockfile = "3rdparty/mypy_lockfile.txt"

and I ran

pants generate-lockfiles ::

and

pants export::

.

pants check ::

runs successfully.

Do you have also python 3.7 as interpreter constraints somewhere in pants.toml?

Nope

[python]

tailor_pex_binary_targets = false

interpreter_constraints = ["CPython==3.11.2"]

enable_resolves = true

Ah ok! Nuke the cache? Yeah not ideal but I don’t know what else could be wrong

Nuke the cache is deleting .pants.d, .pids, dist and the locks?

there is more as you can see in the log.

.cache/pex_root/venvs/5cb0b2dcd2357da2bbde0d877bde9b817c555a3e/fde49d60105c0ef9833901ddf249f36d7deded9a/lib/python3.11/site-packages/numpy/__init__.pyi:641: error: Positional-only parameters are only supported in Python 3.8 and greater

ah thanks!

I will first try with just nuking

pex_root

but there are more https://www.pantsbuild.org/docs/using-pants-in-ci

So deleting the cache for pants and pre-commit didn't do anything

Something wrong with your pre-commit set-up then. This is how it looks like for me. Ah you need to use

pass_filenames: false

- repo: local
    hooks:
      - id: lint-check
        name: Checking source files formatting
        entry: "./pants --changed-since=main --changed-dependees=transitive lint"
        language: script
        types: [python]
        pass_filenames: false
        verbose: true

That did the trick! Wow, thank you so much Shantanu!