## Why
We want actionable build-hotspot data from CI so we can tune Rust
workflow performance (for example, target coverage, cache behavior, and
job shape) based on actual compile-time bottlenecks.
`cargo` timing reports are lightweight and provide a direct way to
inspect where compilation time is spent.
## What Changed
- Updated `.github/workflows/rust-release.yml` to run `cargo build` with
`--timings` and upload `target/**/cargo-timings/cargo-timing.html`.
- Updated `.github/workflows/rust-release-windows.yml` to run `cargo
build` with `--timings` and upload
`target/**/cargo-timings/cargo-timing.html`.
- Updated `.github/workflows/rust-ci.yml` to:
- run `cargo clippy` with `--timings`
- run `cargo nextest run` with `--timings` (stable-compatible)
- upload `target/**/cargo-timings/cargo-timing.html` artifacts for both
the clippy and nextest jobs
Artifacts are matrix-scoped via artifact names so timings can be
compared per target/profile.
## Verification
- Confirmed the net diff is limited to:
- `.github/workflows/rust-ci.yml`
- `.github/workflows/rust-release.yml`
- `.github/workflows/rust-release-windows.yml`
- Verified timing uploads are added immediately after the corresponding
timed commands in each workflow.
- Confirmed stable Cargo accepts plain `--timings` for the compile phase
(`cargo test --no-run --timings`) and generates
`target/cargo-timings/cargo-timing.html`.
- Ran VS Code diagnostics on modified workflow files; no new diagnostics
were introduced by these changes.
## Why
Installing `zstd` via Chocolatey in
`.github/workflows/rust-release-windows.yml` has been taking about a
minute on Windows release runs. This adds avoidable latency to each
release job.
Using DotSlash removes that package-manager install step and pins the
exact binary we use for compression.
## What Changed
- Added `.github/workflows/zstd`, a DotSlash wrapper that fetches
`zstd-v1.5.7-win64.zip` with pinned size and digest.
- Updated `.github/workflows/rust-release-windows.yml` to:
- install DotSlash via `facebook/install-dotslash@v2`
- replace `zstd -T0 -19 ...` with
`${GITHUB_WORKSPACE}/.github/workflows/zstd -T0 -19 ...`
- `windows-aarch64` uses the same win64 upstream zstd artifact because
upstream releases currently publish `win32` and `win64` binaries.
## Verification
- Verified the workflow now resolves the DotSlash file from
`${GITHUB_WORKSPACE}` while the job runs with `working-directory:
codex-rs`.
- Ran VS Code diagnostics on changed files:
- `.github/workflows/rust-release-windows.yml`
- `.github/workflows/zstd`
## Why
`rust-release` cache restore has had very low practical value, while
cache save consistently costs significant time (usually adding ~3
minutes to the critical path of a release workflow).
From successful release-tag runs with cache steps (`289` runs total):
- Alpha tags: cache download averaged ~5s/run, cache upload averaged
~230s/run.
- Stable tags: cache download averaged ~5s/run, cache upload averaged
~227s/run.
- Windows release builds specifically: download ~2s/run vs upload
~169-170s/run.
Hard step-level signal from the same successful release-tag runs:
- Cache restore (`Run actions/cache`): `2,314` steps, total `1,515s`
(~0.65s/step).
- `95.3%` of restore steps finished in `<=1s`; `99.7%` finished in
`<=2s`; `0` steps took `>=10s`.
- Cache save (`Post Run actions/cache`): `2,314` steps, total `66,295s`
(~28.65s/step).
Run-level framing:
- Download total was `<=10s` in `288/289` runs (`99.7%`).
- Upload total was `>=120s` in `285/289` runs (`98.6%`).
The net effect is that release jobs are spending time uploading caches
that are rarely useful for subsequent runs.
## What Changed
- Removed the `actions/cache@v5` step from
`.github/workflows/rust-release.yml`.
- Removed the `actions/cache@v5` step from
`.github/workflows/rust-release-windows.yml`.
- Left build, signing, packaging, and publishing flow unchanged.
## Validation
- Queried historical `rust-release` run/job step timing and compared
cache download vs upload for alpha and stable release tags.
- Spot-checked release logs and observed repeated `Cache not found ...`
followed by `Cache saved ...` patterns.
Windows release builds were compiling and linking four release binaries
on a single runner, which slowed the release pipeline. The
Windows-specific logic also made `rust-release.yml` harder to read and
maintain.
## What Changed
- Extracted Windows release logic into a reusable workflow at
`.github/workflows/rust-release-windows.yml`.
- Updated `.github/workflows/rust-release.yml` to call the reusable
Windows workflow via `workflow_call`.
- Parallelized Windows binary builds with one 4-entry matrix over two
targets (`x86_64-pc-windows-msvc`, `aarch64-pc-windows-msvc`) and two
bundles (`primary`, `helpers`).
- Kept signing centralized per target by downloading both prebuilt
bundles and signing all four executables together.
- Preserved final release artifact behavior and filtered intermediate
`windows-binaries*` artifacts out of the published release asset set.
Michael BolinandGitHub