Cobalt Branching

(This document assumes you are already familiar with Cobalt Versioning practices.)

The Cobalt project uses git branches for two main purposes:

  1. To solidify a release as it is hardened for production.
  2. To isolate master branch developers from risky or disruptive work.

Release Branches

A “Cobalt release” is an official, tested version of Cobalt that is intended to be deployable to production. We branch for releases to allow development to continue on the master branch while stabilizing and finalizing a set of sources for release.

Release Timeline

  1. Feature work is done in the master branch.

  2. Once all feature work is completed, a Release Number is reserved and a branch is created. The branch will be named rc_<release-number> to indicate that the branch represents a release candidate for version <release-number>, and not the final release.

    An RC announcement will be made to

    It should be understood that RC branches are being stabilized and are subject to changes.

  3. As bugs are discovered and feedback received from partners, fixes will be cherry-picked into the release candidate branch. Each update to rc_<release-number> will have an increasing Build ID.

  4. As time goes on, the number of cherry-picks will decrease in number and scope.

  5. Once the branch is deemed to be feature-complete and stable, it will be renamed to release_<release-number>, representing an actual Cobalt release. This means that the RC branch will be removed and the release branch will permanently take its place.

    A release announcement will be made to

  6. The Cobalt project will strongly resist updating released versions, but may need to back-port fixes from time to time. This is especially true if there are any severe security flaws that need to be addressed. So cherry-picks are still possible into release_<release-number> release branches.

    In these rare cases, announcements will be made to

Work Branches

If a set of work is deemed to be particularly risky or disruptive, or if a serious contributor wants a sandbox to prepare an extensive patch, a work branch may be created to facilitate such development.

Work branch names are of the form work_<topic>, where <topic> is the purpose for which the branch was created. Work branches are generally in use by a specific and limited set of people, and may disappear at any time.

Capitalization, Branch Names, and You

Some older branches followed an ALL_CAPS_SNAKE_CASE naming convention. Going forward, branch names will follow a lower_snake_case naming convention.

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