Release Matomo 4.x.0 #15537

Checklists for a successful Matomo release

Work on Beta cycle, towards Release Candidate 1:

• [ ] Beta release cycle has started with the first beta release
• [ ] Tag a new release for matomo-org/referrer-spam-blacklist and matomo-org/searchengine-and-social-list
• [ ] Fetch our latest and greatest home-made libraries with composer update matomo-org/referrer-spam-blacklist matomo-org/searchengine-and-social-list matomo-org/matomo-php-tracker matomo-org/component-network,matomo-org/component-ini,matomo-org/component-decompress,matomo-org/component-cache
• [ ] Fetch the latest composer libraries for all with composer update
• [ ] Up to date submodules
• [ ] Tag the RC candidate
• [ ] Check that the build is green
• [ ] Package & release the Release Candidate
• [ ] Post sticky thread in forum about RC
• [ ] Let translators know about the new RC by posting an announcement here
• [ ] inform RC release on social media
• [ ] update tag manager submodule

Triage PRs and issues:

• [ ] Forum support: regularly check all posts in Support & Bugs forum
• [ ] Forum General questions: look for bugs & regressions in General questions forum
• [ ] Backlog grooming (Matomo core): check issues without milestone and PRs if any one should be fixed in this release
• [ ] Check this list of issues across all Matomo repositories, where the milestone is set to Current sprint
• [ ] Check this list of Pull requests all Matomo repositories, where the milestone is set to Current sprint
• [ ] Triage all PRs not scheduled yet, or close (see also issues without milestone)
• [ ] Make CI builds of our official plugins matomo-org/plugin-* all green

The final checks before the stable release:

• [ ] Release candidate cycle (at least 1 week cycle)
• [ ] Fix all remaining issues in the milestone
• [ ] All open source plugins builds are green on master with latest RC
• [ ] Plugins that needed a version bump are now released on the marketplace
• [ ] Synchronise translations from transifex
• [ ] Submodules are up to date

Prepare the Changelog entry:

• [ ] Mark that the release has a major DB upgrade
• [ ] Use our github changelog generator to generate the changelog using this config.js
• [ ] Add to changelog any new issues or FAQ added since first RC
• [ ] Add to changelog the security issues fixed, if any
• [ ] Do not publish publicly the changelog yet. This also ensures security issues are not publicly visible until the stable release.
• [ ] Change changelog published date to the release day

  Check the developer changelog is complete, by looking over each issue:

• [ ] is this issue relevant to developers? let's mention it in the Developer changelog
• [ ] is this issue's title descriptive and useful to people scanning our changelog?
• [ ] are the right labels applied to the issue? (issues tagged with labels such as Bug, Enhancement, Major are grouped together in the changelog)
• [ ] if this issue was sponsored, we note the sponsor organisation in the changelog.

Merge 4.x-dev branch into master:

• [ ] In https://github.com/matomo-org/matomo/settings get an admin to enable "Merge buttons > Allow merge commits"
• [ ] Create a Pull request to merge 4.x-dev into master, by clicking on "Merge Pull request > Create a merge commit" (not "Squash & merge")
• [ ] In https://github.com/matomo-org/matomo/settings get an admin to disable "Merge buttons > Allow merge commits"

:boom: Release :rocket:

• [ ] Close milestone on Github
• [ ] Release publicly the new stable version by running ./scripts/build-package.sh 4.x.y from here and waiting 5 minutes
• [ ] In Github release we write

## [Matomo x.y.0 Changelog](https://matomo.org/changelog/matomo-y-x-0/)

This Github download (below) is only meant for developers and it will require extra work to install it. 
 * Latest stable production release can be found at https://matomo.org/download/ ([learn more](https://matomo.org/docs/installation/)) (recommended)
 * Beta and Release Candidates releases can be found at https://builds.matomo.org/ ([learn more](http://matomo.org/faq/how-to-update/faq_159/))

• [ ] Take screenshots of new features + draft a blog post showcasing what's new
• [ ] Create this 'Release Matomo 3.*' issue in the next release milestone