la-stack 0.4.2

Fast, stack-allocated linear algebra for fixed dimensions
Documentation
# Releasing la-stack

This guide documents the release flow for `vX.Y.Z`: prepare a dedicated
release PR, merge it, create the final annotated tag from the generated
changelog, publish to crates.io, and create the GitHub release.

The release changelog is generated with `git-cliff --tag` through
`just changelog-unreleased`, so no temporary local tag is needed.

Applies to versions vX.Y.Z. Prefer updating documentation before publishing
to crates.io.

---

## Conventions and environment

Set these variables to avoid repeating the version string:

```bash
# tag has the leading v, version does not
TAG=vX.Y.Z
VERSION=${TAG#v}
```

Verify your git remotes:

```bash
git remote -v
```

Ensure your local `main` is up to date before beginning:

```bash
git checkout main
git pull --ff-only
```

---

## Step 1: Create a clean release PR

This PR should primarily include version bumps, changelog updates, benchmark
comparison updates, and documentation updates. All major code changes should
already be on `main`.

Small, critical fixes discovered during the release process may be included,
but keep them minimal and release-critical.

1. Create the release branch

```bash
git checkout -b "release/$TAG"
```

2. Bump versions

Preferred, if `cargo-edit` is installed:

```bash
cargo set-version "$VERSION"
```

Alternative: edit `Cargo.toml` manually and update `version = "..."` under
`[package]`.

Review version references in documentation:

```bash
rg -n "\bv?[0-9]+\.[0-9]+\.[0-9]+\b" README.md docs/ || true
```

3. Generate the release changelog

```bash
# Generates CHANGELOG.md as though TAG already exists, then applies
# markdown hygiene and archives completed minor release series.
just changelog-unreleased "$TAG"
```

`just changelog-unreleased` runs
`GIT_CLIFF_OFFLINE=true git-cliff --tag "$TAG" -o CHANGELOG.md`, then
`postprocess-changelog`, then `archive-changelog`. The root changelog keeps
Unreleased plus the active minor series; older completed minor series live
under `docs/archive/changelog/`.

4. Run benchmarks and update the README comparison table

```bash
# Run vs_linalg benchmarks (la-stack vs nalgebra vs faer) and update the
# README benchmark table + SVG plot
just bench-vs-linalg
just plot-vs-linalg-readme
```

Review the updated table in `README.md` and the plot in `docs/assets/` for
accuracy.

5. Save an exact-arithmetic benchmark baseline for this release

```bash
# Run exact benchmarks and save a named Criterion baseline
just bench-save-baseline $TAG
```

This baseline can be compared against in future optimization work.
See `docs/BENCHMARKING.md` for the full comparison workflow.

6. Validate the release branch

```bash
just ci
cargo publish --locked --dry-run
```

7. Stage and commit release artifacts

```bash
git add Cargo.toml Cargo.lock CHANGELOG.md README.md docs/

git commit -m "chore(release): release $TAG

- Bump version to $TAG
- Update changelog with latest changes
- Update benchmark comparison table
- Update documentation for release"
```

8. Push the branch and open a PR

```bash
git push -u origin "release/$TAG"
```

PR metadata:

- Title: chore(release): release $TAG
- Description: Clean release PR with version bump, changelog, and
  documentation updates. No feature work.

### Handling fixes discovered during the release process

If you discover issues after generating the changelog:

1. For critical fixes that must be in this release, make and commit the fix,
   then regenerate the release changelog:

   ```bash
   just changelog-unreleased "$TAG"
   git add CHANGELOG.md docs/archive/changelog/
   git commit -m "docs: update changelog with release fixes"
   ```

2. For non-critical fixes, document them as known issues in the release notes
   or include them in the next release.

---

## Step 2: After the PR is merged into main

1. Sync your local `main` to the merge commit

```bash
git checkout main
git pull --ff-only
```

2. Create the final annotated tag using the changelog content

```bash
# Creates the annotated tag from the matching CHANGELOG.md section.
# Archived versions are read from docs/archive/changelog/ automatically.
# For large changelogs (>125KB), the tag message points to the changelog
# section instead of embedding the full content.
just tag "$TAG"
```

3. Optional: verify the tag message content

```bash
git tag -l --format='%(contents)' "$TAG"
```

4. Push the tag

```bash
git push origin "$TAG"
```

5. Publish to crates.io

```bash
# Publish the crate (ensure docs are already updated on main via the PR)
cargo publish --locked
```

6. Create the GitHub release with notes from the tag annotation

```bash
# Requires GitHub CLI (gh) and authenticated session
gh release create "$TAG" --title "$TAG" --notes-from-tag
```

Always set the GitHub release title to the exact tag string, including the
leading `v`.

---

## Notes and tips

- Do not create a temporary local release tag for changelog generation; use
  `just changelog-unreleased "$TAG"`.
- Keep the release PR scoped to version, changelog, archive, benchmark
  comparison, and documentation changes.
- `just changelog` regenerates the current changelog from existing tags and may
  update `docs/archive/changelog/`.
- `just changelog-unreleased "$TAG"` is for release PR preparation before the
  final tag exists.
- `just tag "$TAG"` is for the final post-merge annotated tag.
- If multiple crates or files reference the version, confirm all of them are
  updated consistently.