Ahead of the release of MediaWiki 1.35.0, a number of people have been
working to make sure that MediaWiki is compatible with PHP 7.4. We have
now reached the final phase of that work, where we are checking that we
don't regress in CI. This is running on the master branch, as REL1_34 is
To that end, * Wikimedia CI is now running PHP 7.4 as voting* for almost
all PHP code. This covers MediaWiki core, most extensions, skins, and
libraries. PHP74 jobs will appear in the 'gate-and-submit' and 'php'
pipelines for your projects.
If your code works in PHP 7.3 but not in PHP 7.4, it will now fail. Most of
the changes are documented in PHP's migration guidance. Note that this
is rare; almost all PHP 7.2- and 7.3-compatible code works fine in PHP 7.4.
There are a few extensions which are known to not yet be PHP
7.4-compatible, and so currently aren't running PHP74 tests yet; others
will probably exist. I've spot-checked a few dozen projects, and fixed
several issues, but it is likely that I have missed some; we have well over
a thousand repos, after all.
If your repo is broken by this change and needs the PHP 7.4 testing
temporarily removed, please file a task on the workboard and I'll be
happy to get it fixed.
Thank you to everyone who has worked on this.
 - https://phabricator.wikimedia.org/T233012
 - https://www.php.net/manual/en/migration74.php
 - https://phabricator.wikimedia.org/tag/php_7.4_support/
*James D. Forrester* (he/him <http://pronoun.is/he> or they/themself
Wikimedia Foundation <https://wikimediafoundation.org/>