## Why
PR #16130 fixed the Windows `argument-comment-lint` regression in
`rust-ci-full`, but the next `main` runs still left the Linux and macOS
lint legs timing out.
In [run
23695263729](https://github.com/openai/codex/actions/runs/23695263729),
both non-Windows `argument-comment-lint` jobs were cancelled almost
exactly 30 minutes after they started. The remaining workflow difference
versus `rust-ci.yml` was that `rust-ci-full` did not pass
`BUILDBUDDY_API_KEY` into the non-Windows Bazel lint step, so
`run-bazel-ci.sh` fell back to local Bazel configuration instead of
using the faster remote-backed path available on `main`.
## What changed
- passed `BUILDBUDDY_API_KEY` to the non-Windows `rust-ci-full`
`argument-comment-lint` Bazel step
- left the Windows packaged-wrapper path from #16130 unchanged
- kept the change scoped to `rust-ci-full.yml`
## Test plan
- loaded `.github/workflows/rust-ci-full.yml` and
`.github/workflows/rust-ci.yml` with `python3` + `yaml.safe_load(...)`
- inspected run `23695263729` and confirmed `Argument comment lint -
Linux` and `Argument comment lint - macOS` were cancelled about 30
minutes after start
- verified the updated `rust-ci-full` step now matches the non-Windows
secret wiring already present in `rust-ci.yml`
## References
- #16130
- #16106
## Why
PR #16106 switched `rust-ci-full` over to the native Bazel-backed
`argument-comment-lint` path on all three platforms.
That works on Linux and macOS, but the Windows leg in `rust-ci-full` now
fails before linting starts: Bazel dies while building `rules_rust`'s
`process_wrapper` tool, so `main` reports an `argument-comment-lint`
failure even though no Rust lint finding was produced.
Until native Windows Bazel linting is repaired, `rust-ci-full` should
keep the same Windows split that `rust-ci.yml` already uses.
## What changed
- restored the Windows-only nightly `argument-comment-lint` toolchain
setup in `rust-ci-full`
- limited the Bazel-backed lint step in `rust-ci-full` to non-Windows
runners
- routed the Windows runner back through
`tools/argument-comment-lint/run-prebuilt-linter.py`
- left the Linux and macOS `rust-ci-full` behavior unchanged
## Test plan
- loaded `.github/workflows/rust-ci-full.yml` and
`.github/workflows/rust-ci.yml` with `python3` + `yaml.safe_load(...)`
- inspected failing Actions run `23692864849`, especially job
`69023229311`, to confirm the Windows failure occurs in Bazel
`process_wrapper` setup before lint output is emitted
## References
- #16106
## Why
`argument-comment-lint` had become a PR bottleneck because the repo-wide
lane was still effectively running a `cargo dylint`-style flow across
the workspace instead of reusing Bazel's Rust dependency graph. That
kept the lint enforced, but it threw away the main benefit of moving
this job under Bazel in the first place: metadata reuse and cacheable
per-target analysis in the same shape as Clippy.
This change moves the repo-wide lint onto a native Bazel Rust aspect so
Linux and macOS can lint `codex-rs` without rebuilding the world
crate-by-crate through the wrapper path.
## What Changed
- add a nightly Rust toolchain with `rustc-dev` for Bazel and a
dedicated crate-universe repo for `tools/argument-comment-lint`
- add `tools/argument-comment-lint/driver.rs` and
`tools/argument-comment-lint/lint_aspect.bzl` so Bazel can run the lint
as a custom `rustc_driver`
- switch repo-wide `just argument-comment-lint` and the Linux/macOS
`rust-ci` lanes to `bazel build --config=argument-comment-lint
//codex-rs/...`
- keep the Python/DotSlash wrappers as the package-scoped fallback path
and as the current Windows CI path
- gate the Dylint entrypoint behind a `bazel_native` feature so the
Bazel-native library avoids the `dylint_*` packaging stack
- update the aspect runtime environment so the driver can locate
`rustc_driver` correctly under remote execution
- keep the dedicated `tools/argument-comment-lint` package tests and
wrapper unit tests in CI so the source and packaged entrypoints remain
covered
## Verification
- `python3 -m unittest discover -s tools/argument-comment-lint -p
'test_*.py'`
- `cargo test` in `tools/argument-comment-lint`
- `bazel build
//tools/argument-comment-lint:argument-comment-lint-driver
--@rules_rust//rust/toolchain/channel=nightly`
- `bazel build --config=argument-comment-lint
//codex-rs/utils/path-utils:all`
- `bazel build --config=argument-comment-lint
//codex-rs/rollout:rollout`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/16106).
* #16120
* __->__ #16106
## Summary
Split the old all-in-one `rust-ci.yml` into:
- a PR-time Cargo workflow in `rust-ci.yml`
- a full post-merge Cargo workflow in `rust-ci-full.yml`
This keeps the PR path focused on fast Cargo-native hygiene plus the
Bazel `build` / `test` / `clippy` coverage in `bazel.yml`, while moving
the heavyweight Cargo-native matrix to `main`.
## Why
`bazel.yml` is now the main Rust verification workflow for pull
requests. It already covers the Bazel build, test, and clippy signal we
care about pre-merge, and it also runs on pushes to `main` to re-verify
the merged tree and help keep the BuildBuddy caches warm.
What was still missing was a clean split for the Cargo-native checks
that Bazel does not replace yet. The old `rust-ci.yml` mixed together:
- fast hygiene checks such as `cargo fmt --check` and `cargo shear`
- `argument-comment-lint`
- the full Cargo clippy / nextest / release-build matrix
That made every PR pay for the full Cargo matrix even though most of
that coverage is better treated as post-merge verification. The goal of
this change is to leave PRs with the checks we still want before merge,
while moving the heavier Cargo-native matrix off the review path.
## What Changed
- Renamed the old heavyweight workflow to `rust-ci-full.yml` and limited
it to `push` on `main` plus `workflow_dispatch`.
- Added a new PR-only `rust-ci.yml` that runs:
- changed-path detection
- `cargo fmt --check`
- `cargo shear`
- `argument-comment-lint` on Linux, macOS, and Windows
- `tools/argument-comment-lint` package tests when the lint itself or
its workflow wiring changes
- Kept the PR workflow's gatherer as the single required Cargo-native
status so branch protection can stay simple.
- Added `.github/workflows/README.md` to document the intended split
between `bazel.yml`, `rust-ci.yml`, and `rust-ci-full.yml`.
- Preserved the recent Windows `argument-comment-lint` behavior from
`e02fd6e1d3` in `rust-ci-full.yml`, and mirrored cross-platform lint
coverage into the PR workflow.
A few details are deliberate:
- The PR workflow still keeps the Linux lint lane on the
default-targets-only invocation for now, while macOS and Windows use the
broader released-linter path.
- This PR does not change `bazel.yml`; it changes the Cargo-native
workflow around the existing Bazel PR path.
## Testing
- Rebasing this change onto `main` after `e02fd6e1d3`
- `ruby -e 'require "yaml"; %w[.github/workflows/rust-ci.yml
.github/workflows/rust-ci-full.yml .github/workflows/bazel.yml].each {
|f| YAML.load_file(f) }'`
