This provides a native harness with several advantages over
`pre-commit`:
- Faster when initializing the cache
- Smaller cache sizes: under 43mb compared to over 62mb
- Better integration with `uv` for Python usage
Steps for migrating for existing contributors:
1. Install `prek` following instructions in the updated docs.
2. Replace hooks in an existing checkout with a special flag:
```sh
prek install --overwrite
```
The `--overwrite` flag is what removes the old hooks.
If you used the pre-push variant:
```sh
prek install --hook-type pre-push --overwrite
```
3. Optional cleanups:
```sh
rm -rf ~/.cache/pre-commit # reclaim the old hook-environment cache
pipx uninstall pre-commit # if installed via pipx; or `brew uninstall
pre-commit`
```
Assisted-by: Antigravity with Gemini
Not sure how these got missed when moving other things to `uv`, but this
should clean them up.
The bump to Python 3.12 is so that we can use `@override` with the
simple import from `typing`. This is needed by the newest versions of
`ty` to do type checking. Added the relevant `@override` annotations.
Assisted-by: Antigravity with Gemini
This removes the need to install any specific version of Python or
figure out how to configure it by instead asking users to install `uv`
and letting it manage Python. Among other advantages, `uv` is designed
to be fast enough to embed directly into our scripts.
We were already using this in `bench_runner.py` so that the script could
import non standard library dependencies. Moving to it for the rest of
our Python unifies the approach and will also enable dependencies
whenever needed.
I've left `github_tools` alone as it has special handling with its own
Bazel setup.
I've updated the contributing tools to explain the approach here.
First, this makes the Bazel invocations not try to uses curses which
prevents running them with `pre-commit run ... -v` showing the timings
for each check. The curses display overwrote the output.
Second, this fixes the main slowdown I was seeing. Because we passed
_all_ files to the check-build-graph hook and there are large number of
files, pre-commit would run the tool over and over on a subset of the
files. This is especially wasteful as the build graph check already
doesn't do anything with the files, it just checks `//...` on each
invocation. So this just added a (large) constant factor of cost.
Third, this tries to reduce the cost of `fix_cc_deps.py` in the case of
large numbers of files. This still isn't _super_ fast -- but the rest of
the cost is in running the `bazel query` and parsing the output. I tried
switching it to jsonproto and it wasn't any faster. I think this would
need to be in a non-Python language and use `proto` directly to
significantly improve the cost here.
Assisted-by: Antigravity with Gemini
Chandler Carruth
Geoff Romer