--- layout: developer-doc title: Release Policy category: distribution tags: [distribution, release, release-policy, policy] order: 3 --- # Release Policy As an open-source project and programming language, it is incredibly important that we have a well-defined release policy. This document defines said policy. > **Once a release has been made it is immutable. The release should only ever > be edited to mark it as broken. Nothing else should ever be changed.** > > **No two release workflows can be running at once, to avoid race conditions > since releases > [must update files in S3](fallback-launcher-release-infrastructure.md#updating-the-release-list). > Make sure that tags which trigger release builds are pushed sequentially, only > pushing the next one after the previous build has finished.** - [Versioning](#versioning) - [Launcher Versioning](#launcher-versioning) - [Release Branches](#release-branches) - [Release Workflow](#release-workflow) - [Breaking Release Workflow](#breaking-release-workflow) - [Tag Naming](#tag-naming) - [Manifest Files](#manifest-files) - [Breaking Changes to Launcher Upgrade](#breaking-changes-to-launcher-upgrade) - [GitHub Releases](#github-releases) - [Release Notes](#release-notes) - [Version Support](#version-support) - [Working on the Current Release](#working-on-the-current-release) - [Backporting Fixes](#backporting-fixes) ## Versioning Releases of Enso are versioned using [semantic versioning](https://semver.org). Where `a.b.c-tag` is the version string, `a` is the major version, `b`, is the minor version, `c` is the patch version, and `tag` is additional metadata, the following hold: - Breaking changes to language behaviour or the public API will result in a major version increase. - Addition of functionality in a backwards-compatible manner will result in a minor version increase. - Backwards-compatible bug fixes will result in a patch version increase. - The tag will indicate pre-release or beta versions, and will increase when any pre-release change is made. These are not intended to be stable. ### Launcher Versioning The launcher is released alongside Enso releases, so the launcher version is tied to the Enso version that it is released with. ## Release Branches A release branch in the Enso repository is a branch prefixed with `release/`. Release branches obey the following rules: - One release branch exists per major version, and is named `release/n.x`, where `n` is the major version, and the rest is literal. - A release branch must contain _tags_ corresponding to released versions of Enso. Once a release has been made, no further changes may be made to that release. - A tagged release must contain a `RELEASES.md` file that describes the changes contained in that release. It should be noted that general development still takes place on the `main` branch of the repository. ## Release Workflow Cutting a release for Enso proceeds as follows: 1. If no release branch exists for the current major version, one should be created. 2. Create a branch called `wip/`. For example: ``` git tag --sign enso-0.2.11 ``` 12. Push the tag to the remote (using `git push --follow-tags`). This will start the release build automatically. 13. CI will create a draft release for this tag, as well as build and upload the appropriate artefacts. **Do not** create a release for this tag manually. 14. The release notes for the version being released should be copied from the new section in `RELEASES.md` into the GitHub release description with the line breaks removed. 15. The title of the release should be `Enso Engine ` (e.g. `Enso Engine 0.2.11`). 16. Once verification has been performed, the release can be published. It should _not_ be a pre-releases as we reserve these for nightly builds. ### Breaking Release Workflow If, however, the engine needs to release but the `HEAD` of `main` is not in a compatible state with the IDE, the process has to differ a little bit. Please note that the instructions here are more vague than the above, as exactly what is required may vary based on the situation. Consider a scenario where there are four new commits since the last release: `wwwwwww`, `xxxxxxx`, `yyyyyyy`, `zzzzzzz`. The commit `yyyyyyy` contains breaking changes that are _not yet integrated with the IDE_. Releasing a package containing that commit (and those that depend on it) would break the IDE, but we nevertheless want to release as much as possible: 1. If no release branch exists for the current major version, one should be created. 2. Rebase the commits that are wanted onto the release branch: ``` git rebase --onto origin/release/0.x wwwwwww~1 xxxxxxx ``` 3. This will put you into a "detached HEAD" state at commit `aaaaaaa`, so you need to make a new branch: `git branch release-update aaaaaaa`, whose `HEAD` commit is the same as `xxxxxxx`. 4. This new branch is a fast-forward merge away from the release branch. Check out the release branch and then fast-forward merge `release-update` into it. For example: ``` git checkout release/0.x git merge --ff-only release-update ``` 5. On the release branch, ensure that the release notes are up to date in `RELEASES.md` (follow the existing format), and that the new version number and edition name have been set in `build.sbt`. This version and edition name should _not_ contain `SNAPSHOT`. 6. Run `sbt "stdlib-version-updater/run update"` to update the standard library versions. 7. Once this is done, create a tag for the commit at the HEAD of the release branch. It should be named as above. The tag message should be `Enso `. For example: ``` git tag --sign enso-0.2.11 ``` 7. Push the tag to the remote. This will start the release build. 8. CI will create a draft release for this tag, as well as build and upload the appropriate artefacts. **Do not** create a release for this tag manually. 9. The release notes for the version being released should be copied from the new section in `RELEASES.md` into the GitHub release description with the line breaks removed. 10. The title of the release should be `Enso Engine ` (e.g. `Enso Engine 0.2.11`). 11. Check out the main branch, and then synchronise the changes to `RELEASES.md` on the release branch with the changes on `main`. 12. In the same commit, Update the build version number in `build.sbt` to the new snapshot version. If unclear, bump the patch version by one and append `-SNAPSHOT` (e.g. `0.2.10` becomes `0.2.11-SNAPSHOT`). The edition name should have the number after the dot increased and `-SNAPSHOT` appended, so that `2021.3` becomes `2021.4-SNAPSHOT`. The message should be `Bump the snapshot version`. After changing the version in `build.sbt`, remember to run `sbt "stdlib-version-updater/run update"` to update the library versions again. 13. Push this commit into `origin/main`, or merge via PR if unable to directly push. It is recommended that you instigate a freeze on merges to `main` whilst performing this process. ### Tag Naming Tags for releases are named as follows `enso-version`, where `version` is the semver string (see [versioning](#versioning)) representing the version being released. ### Manifest Files Manifest files are used to describe metadata about various releases for use by the Enso tooling. #### Engine Manifest Each GitHub release contains an asset named `manifest.yaml` which is a YAML file containing metadata regarding the release. The manifest is also included in the root of an Enso version package. It has at least the following fields: - `minimum-launcher-version` - specifies the minimum version of the launcher that should be used with this release of Enso, - `minimum-project-manager-version` - specifies the minimum version of the project manager that should be used with this release of Enso; currently it is the same as the launcher version but this may change in the future, - `graal-vm-version` - specifies the exact version of GraalVM that should be used with this release of Enso, - `graal-java-version` - as GraalVM versions may have different variants for different Java versions, this specifies which variant to use. The minimum launcher and project manager versions are kept as separate fields, because at some point the same runtime version management logic may be associated with different versions of these components. It can also contain the following additional fields: - `jvm-options` - specifies a list of options that should be passed to the JVM running the engine. These options can be used to fine-tune version specific optimization settings etc. Each option must have a key called `value` which specifies what option should be passed. That value can include a variable `$enginePackagePath` which is substituted with the absolute path to the root of the engine package that is being launched. Optionally, the option may define `os` which will restrict this option only to the provided operating system. Possible `os` values are `linux`, `macos` and `windows`. - `broken` - can be set to `true` to mark this release as broken. This field is never set in a release. Instead, when the launcher is installing a release marked as broken using the `broken` file, it adds this property to the manifest to preserve that information. For example: ```yaml minimum-launcher-version: 0.0.1 minimum-project-manager-version: 0.0.1 jvm-options: - value: "-Dpolyglot.engine.IterativePartialEscape=true" - value: "-Dtruffle.class.path.append=$enginePackagePath\\component\\runtime.jar" os: "windows" - value: "-Dtruffle.class.path.append=$enginePackagePath/component/runtime.jar" os: "linux" - value: "-Dtruffle.class.path.append=$enginePackagePath/component/runtime.jar" os: "macos" graal-vm-version: 20.2.0 graal-java-version: 11 ``` The `minimum-launcher-version` should be updated whenever a new version of Enso introduces changes that require a more recent launcher version. This value is stored in [`distribution/manifest.template.yaml`](../../distribution/manifest.template.yaml) and other values are added to this template at build time. #### Launcher Manifest Additionally, each release should contain an asset named `launcher-manifest.yaml` which contains launcher-specific release metadata. It contains the following fields: - `minimum-version-for-upgrade` - specifies the minimum version of the launcher that is allowed to upgrade to this launcher version. If a launcher is older than the version specified here it must perform the upgrade in steps, first upgrading to an older version newer than `minimum-version-for-upgrade` and only then, using that version, to the target version. This logic ensures that if a newer launcher version required custom upgrade logic not present in older versions, the upgrade can still be performed by first upgrading to a newer version that does not require the new logic but knows about it and continuing the upgrade with that knowledge. - `files-to-copy` - a list of files that should be copied into the distribution's data root. This may include the `README` and similar files, so that after the upgrade these additional files are also up-to-date. These files are treated as non-essential, i.e. an error when copying them will not cancel the upgrade (but it should be reported). - `directories-to-copy` - a list of directories that should be copied into the distribution's data root. Acts similarly to `files-to-copy`. A template manifest file, located in [`distribution/launcher-manifest.yaml`](../../distribution/launcher-manifest.yaml), is automatically copied to the release. If any new files or directories are added or a breaking change to the upgrade mechanism is being made, this manifest template must be updated accordingly. ### Breaking Changes to Launcher Upgrade If at any point the launcher's upgrade mechanism needs an update, i.e. additional logic must be added that was not present before, special action is required. First, the additional logic has to be implemented and a new launcher version should be released which includes this additional logic, but does not require it yet. Then, another version can be released that can depend on this new logic and its `minimum-version-for-upgrade` has to be bumped to that previous version which already includes new logic but does not depend on it. This way, old launcher versions can first upgrade to a version that contains the new logic (as it does not depend on it yet, the upgrade is possible) and using that new version, upgrade to the target version that depends on that logic. ### GitHub Releases A release is considered _official_ once it has been made into a release on [GitHub](https://github.com/enso-org/enso/releases). Once official, a release may not be changed in any way, except to mark it as broken. #### Release Assets Structure Each release contains a build of the Enso engine and native launcher binaries for each supported platform. Moreover, for convenience, it should include bundles containing native launcher binaries and the latest engine build for each platform. So each release should contain the following assets: - `enso-bundle--linux-amd64.tar.gz` - `enso-bundle--macos-amd64.tar.gz` - `enso-bundle--windows-amd64.zip` - `enso-engine--linux-amd64.tar.gz` - `enso-engine--macos-amd64.tar.gz` - `enso-engine--windows-amd64.zip` - `enso-launcher--linux-amd64.tar.gz` - `enso-launcher--macos-amd64.tar.gz` - `enso-launcher--windows-amd64.zip` - `manifest.yaml` #### Marking a Release as Broken We intend to _never_ delete a release from GitHub, as users may have projects that depend on specific versions of Enso. Instead, we provide a mechanism for marking releases as broken that works as follows: - An empty file named `broken` is uploaded to the release. - The release description is edited to visibly mark the release as broken. A broken release is one that _must not_ be downloaded by the launcher unless a project specifies _an exact version match_, and it _must not_ be used in new projects by the launcher unless _explicitly_ specified by the user as an exact version match. When the release is marked as broken at GitHub, a GitHub Actions [Workflow](fallback-launcher-release-infrastructure.md#marking-the-release-as-broken) is triggered that also updates the release in the fallback mechanism. Given its current implementation is prone to race conditions when updating releases, the `broken` file should be added to releases one by one, making sure that only one update workflow is running at the same time and that no release workflows are running in parallel with it. In an unusual situation in which you want to upload a release that is marked as broken from the start, you should first publish it in a non-broken state and only mark it as broken after publishing. That is because the GitHub Workflow that will persist the broken mark to S3 is not triggered for release drafts. > **When marking the release as broken, you should make sure that the workflow > persisting the broken mark to Se has succeeded and re-run it if necessary.** ### Release Notes Release notes should contain a summary of the changes made between the last release and the current release. They should follow the template given below, and are contained in the `RELEASES.md` file in the repository root. ```md # Enso x.y.z (YYYY-MM-DD) ## Language - A list of language-level changes. ## Interpreter/Runtime - A list of changes to the Enso interpreter. ## Type System - A list of type-system changes. ## Tooling - A list of changes to the Enso language tooling. ## Libraries - A list of changes to the Enso core libraries. ## Stabilised Features - A list of stabilised APIs and/or features. ## Misc - A list of miscellaneous changes. ## Internal Only - A list of changes that do not have user-facing impact, but represent significant improvements to the internals of Enso and related tools. ``` If there are no changes for a section, the section may be removed. The releases file is an ongoing record of changes, and may diverge between `main` and the various release branches. ## Version Support We aim to support a given major version for some period of time after the release of the next major version. For a detailed breakdown of the major versions that are currently supported, please see the [security](./security.md) document. ## Working on the Current Release When working on the current release, development should take place against the `main` branch. When it is time to cut a release, the new commits on the main branch are cherry-picked onto the current release branch. From there, the release proceeds as described in [release workflow](#release-workflow) above. ## Backporting Fixes Supporting a major version for some time after the release of the next major version will sometimes require backporting a fix to the previous major version from the current version or from `main`. Backporting should only be used for applying _fixes_, not the addition of new features. The process for performing such a backport is as follows: 1. Create a new branch called `backport/version/fix-name`, where `version` matches the version string of the corresponding release branch. This branch should branch off the corresponding release branch. 2. Back-port the fix to the newly created `backport` branch. This can be done by: - Cherry-picking the commit and performing fixups (preferred). - Re-implementing the fix manually (if cherry-picking will not work due to progression of the codebase). 3. Submit your `backport/version/fix-name` branch for review as a pull-request into the `release/version` branch. 4. Once the PR has passed CI and been approved by the appropriate reviewers, it can be merged into the release branch.