Committing in Materialize

Read doc/developer/guide-changes.md for the full conventions on submitting and reviewing changes.

Pre-commit checklist

Before committing, run these and fix any warnings:

1. bin/fmt (formats .rs, .py, and .proto files)
2. bin/lint (can error if tools are missing; use bin/ci-builder run stable bin/lint as an alternative)
3. cargo clippy --all-targets -- -D warnings

Do not manually update *.snap files. Use cargo test followed by cargo insta accept to update snapshot files. Rewrite datadriven test expectations with REWRITE=1 cargo test ....

PR titles and commit messages

Materialize uses squash merging, so the PR title becomes the commit subject on main.

• Use imperative mood: "Fix X" not "Fixed X" or "Fixes X".
• Be specific: "Fix panic in catalog sync when controller restarts" not "Fix bug".
• Prefix with area if helpful: adapter: , storage: , compute: , sql: .

Write a thorough PR description explaining the rationale for the change. Mention which tests were added or modified in the pull request description, but do not list which tests were run. To auto-close issues, include Fixes database-issues#NNNN. Add release notes for user-visible changes (should complete "This release will...").

Cargo.lock discipline

Never regenerate the entire Cargo.lock — bare cargo update bumps every semver-compatible dep and introduces unrelated breakage (e.g., os_info pulling in objc2 on macOS, chrono-tz changing timezone data, serde_path_to_error changing error formats).

• Adding a dep or changing features: just cargo check. It updates only what's needed.
• Updating one crate: cargo update -p <crate> (add --precise <ver> to pin).
• After any Cargo.lock change, review the diff:

  git diff Cargo.lock | grep '^[+-]version' | head -40
  

  Pin back anything that moved unexpectedly: cargo update -p <crate> --precise <old-version>.
• After rebase conflicts in Cargo.lock: resolve by taking HEAD's version then running cargo check (not cargo update). This preserves existing pins while adding only what the new commits require.

Git conventions

• Work against the main branch of MaterializeInc/materialize.
• Push branches to your fork.
• Pull requests target main on MaterializeInc/materialize.
• Each PR should contain one semantic change.