pre-commit fixes

Author: evertlammerts

.github/workflows/code_quality.yml

@@ -42,4 +42,4 @@ jobs:
 
       - name: pre-commit (--all-files)
         run: |
-          uvx pre-commit run --show-diff-on-failure --color=always --all-files
+          uvx --python 3.12 pre-commit run --show-diff-on-failure --color=always --all-files

.pre-commit-config.yaml

@@ -29,12 +29,6 @@ repos:
     rev: v0.6.13
     hooks:
       - id: cmake-format
-        # cmakelang is unmaintained and crashes under Python 3.14
-        # ("Cannot use capturing groups in re.Scanner"). Pin this hook's
-        # environment to 3.13 so it never picks up a 3.14 interpreter. The
-        # code_quality CI job provisions Python 3.13 to match, so the hook
-        # resolves to the running interpreter there.
-        language_version: python3.12
 
   - repo: https://github.com/pre-commit/mirrors-mypy
     rev: v1.18.2

CLAUDE.md

@@ -188,8 +188,11 @@ uv run ruff format src/ tests/
 # Type checking (mypy — strict mode, see [tool.mypy] in pyproject.toml)
 uv run mypy
 
-# Pre-commit hooks (configured in .pre-commit-config.yaml)
-uvx pre-commit run --all-files
+# Pre-commit hooks (configured in .pre-commit-config.yaml). Install pinned to 3.12
+# (cmakelang crashes on 3.14; keeps hooks off the build interpreter):
+uv tool install --python 3.12 pre-commit
+pre-commit install          # git hook, runs on commit
+pre-commit run --all-files  # run across the tree
 ```
 
 ## Debugging

CONTRIBUTING.md

@@ -4,6 +4,18 @@
 
 See the [instructions on duckdb.org](https://duckdb.org/docs/stable/dev/building/python).
 
+### Pre-commit hooks
+
+Formatting and linting run through [pre-commit](https://pre-commit.com). Install it pinned to Python 3.12 (the `cmake-format` hook's `cmakelang` dependency crashes on 3.14) so the hooks stay independent of your build interpreter, which may be 3.13 or 3.14t:
+
+```bash
+uv tool install --python 3.12 pre-commit
+pre-commit install          # git hook, runs on `git commit`
+pre-commit run --all-files  # run across the tree
+```
+
+The same checks run in CI.
+
 ## General Guidelines
 
 ### **Did you find a bug?**