Swift.org – Swift 5.3 Release Process

March 25, 2020

This post describes the goals, release process, and estimated schedule for Swift 5.3.

Motivation and Goals

Swift 5.3 is a release meant to include significant quality and performance enhancements. In addition, this release will expand the number of platforms where Swift is available and supported, notably adding support for Windows and additional Linux distributions.

Snapshots of Swift 5.3

Downloadable snapshots of the Swift 5.3 release branch will be posted
regularly as part of continuous integration testing. As support is available, snapshot downloads will be added for newly supported platforms.

Once Swift 5.3 is released, the official final builds will also be posted in addition to the snapshots.

Getting Changes into Swift 5.3

On April 20, 2020 the release/5.3 branch will be cut in the swift repository and most related project repositories. Please note the new branch naming scheme. This will contain the changes that will be released in Swift 5.3. After the branch is cut, changes can be landed on the branch via pull request if they meet the criteria for the release.

A few projects will cut their Swift 5.3 branches on different dates:

The same policies will apply to these projects: once the branch is cut, changes can be landed on the branch via pull request if they meet the criteria for the release.

Philosophy on Taking Changes into Swift 5.3

• All language and API changes for Swift 5.3 will go through the Swift
  Evolution process. Evolution
  proposals should aim to be completed by the branch date in order to
  increase their chances of impacting the Swift 5.3 release. Exceptions
  will be considered on a case-by-case basis, particularly if they tie
  in with the core goal of the release.

• Other changes (e.g., bug fixes, diagnostic improvements, SourceKit interface
  improvements) will be accepted based on their risk and impact.

• Low-risk test tweaks will also be accepted late into the release branch if
  it aids in the qualification of the release.

• As the release converges, the criteria for accepted changes will become
  increasingly restrictive.

Impacted Repositories

The following repositories will have a release/5.3 branch to track
sources as part of Swift 5.3 release:

The llvm-project will have a corresponding swift/release/5.3 branch.

Release Managers

The overall management of the release will be overseen by the following
individuals, who will announce when stricter control of change goes into
effect for the Swift 5.3 release as the release converges.

For the Swift 5.3 release, we are adding release managers for each of our supported platforms. They will oversee platform specific issues as well as qualification of that platform for the release.

Platform Release Managers

Please feel free to post on the development forum
or contact Ted Kremenek directly concerning any questions about the release management
process.

Pull Requests for Release Branch

In order for a pull request to be considered for inclusion in the release
branch (release/5.3) after it has been cut, it must include the following
information:

• Explanation: A description of the issue being fixed or enhancement being
  made. This can be brief, but it should be clear.

• Scope: An assessment of the impact/importance of the change. For
  example, is the change a source-breaking language change, etc.

• SR Issue: The SR if the change fixes/implements an issue/enhancement on
  bugs.swift.org.

• Risk: What is the (specific) risk to the release for taking this change?

• Testing: What specific testing has been done or needs to be done to
  further validate any impact of this change?

• Reviewer: One or more code owners
  for the impacted components should review the change. Technical review can
  be delegated by a code owner or otherwise requested as deemed appropriate or
  useful.

All changes going on the release/5.3 branch must go through pull requests that are
accepted by the corresponding release manager.