Newton Release Changelog

Pending user-facing changes live in Towncrier fragments under changelog/. CHANGELOG.md is generated only on a release branch. Shipped sections are immutable; the assembled section for the pending release remains a rolling document until tagging. Follow changelog/README.md as the command and format authority.

Audit pending changes

1. Identify the release ref and comparison base. Audit release-X.Y once it exists; otherwise audit the intended main ref.
2. Protect released history. Diff CHANGELOG.md from the latest stable tag and require explicit maintainer approval for edits to dated sections.
3. Render a non-mutating preview, which also validates Towncrier's renderable fragment filenames:

   uvx --from towncrier==25.8.0 towncrier build --draft \
     --version X.Y.Z --date YYYY-MM-DD
   

4. Compare the preview with the release audit and commit range from the previous release. Inspect .skip reasons separately.
5. Preserve information. Rephrase, split, merge, or recategorize fragments only when the facts remain intact. Ask before deleting information or downgrading a user-visible change.
6. Use only Added, Changed, Deprecated, Removed, and Fixed, in that order. Keep migration and retesting guidance in affected entries.
7. Remove exact and semantic duplicates. When a feature and its fix both land in one cycle, describe the final user-visible behavior once.
8. Keep Added for new public APIs, options, features, examples, and docs. Put existing-API behavior, warning, default, importer, and solver changes in Changed, even when they expand support.
9. Give every breaking, removed, deprecated, or default-changing entry a concrete action. Never direct users to newton._src.
10. A numeric fragment identifier is a GitHub issue number. Towncrier renders its issue link automatically; do not rewrite it as a pull request number.

Assemble the release during RC stabilization

After the initial release scope has been audited on release-X.Y, assemble the current fragments early enough for maintainer review:

uvx --from towncrier==25.8.0 towncrier build --draft \
  --version X.Y.Z --date YYYY-MM-DD
uvx --from towncrier==25.8.0 towncrier build --yes \
  --version X.Y.Z --date YYYY-MM-DD
git rm --ignore-unmatch "changelog/*.skip"
git add -A CHANGELOG.md changelog

Review and approve the draft before running the mutating command. Towncrier inserts the dated section below [Unreleased] and deletes rendered fragments. It ignores .skip files, so remove those explicitly. Review the staged diff in a changelog-only pull request labeled release-management.

After assembly, apply the audit rules above to the dated section: verify completeness, grouping, deduplication, wording, categories, and migration guidance. Keep editorial cleanup in the changelog-management commits that will later be synchronized to main.

The first Towncrier release requires one migration audit. The insertion marker sits above the legacy [Unreleased] entries so they remain under the first generated release title. Merge duplicate category headings without dropping or duplicating an entry. Later releases need no special handling.

Treat the assembled section as a rolling document. For every later cherry-pick before tagging:

1. Validate the new fragments and render them with towncrier build --draft.
2. Fold the previewed entries into the existing dated section without creating a second release heading.
3. Delete exactly the consumed .md and .skip fragments, then stage CHANGELOG.md and changelog/.
4. Rerun the changelog cleanup and release-audit checks, and merge the update as another changelog-only release-management pull request.

Final GA preparation verifies the completed section and confirms that no release-branch fragments remain. Do not postpone the full cleanup until GA.

Synchronize to main

After tagging:

1. Create a changelog-only branch from current main.
2. Cherry-pick, in order, every changelog-management commit from release-X.Y: the initial Towncrier build, editorial cleanup, and all later cherry-pick additions.
3. Confirm fragments deleted by those commits disappear while fragments added to main after the branch cut remain under changelog/.
4. Confirm the dated section matches the release tag and older history is unchanged.
5. Open a changelog-only pull request labeled release-management.

Do not replace the whole file with the release-branch copy. The commits' path-level deletions are what preserve main-only fragments.

Checks

uvx --from towncrier==25.8.0 towncrier build --draft \
  --version X.Y.Z --date YYYY-MM-DD
git diff v<latest-release> -- CHANGELOG.md changelog
git diff --cached --name-status -- CHANGELOG.md changelog
rg -ni "removed|deprecated|in favor of|use .* instead|renam|replac|default|breaking" \
  CHANGELOG.md changelog

Confirm that [Unreleased] is empty after the first migration, no dated history changed, released entries appear exactly once, and post-cut main fragments survive synchronization.