All,
Over the US holiday weekend, PHP 7.4.0 final was released, and so I've made it available in Wikimedia CI as an experimental job.[0]
Although it will generally work as a drop-in replacement for PHP 7.3.x testing, because of the breadth and depth of our code bases it's likely that there will be some issues; there are already some known problems with MediaWiki core and extensions.[1]
If you and other owners of your codebase wants to enable PHP74, you can run 'check experimental' on a patch in gerrit to see if it passes already.
If it does pass, enabling it is pretty trivial (e.g. for Parsoid it worked immediately[2]) – just file a quite Phabricator task on #Continuous-Integration-Config[3] and we'll get it done. If your codebase doesn't work in PHP74 yet, drop into #wikimedia-dev or #wikimedia-tech IRC and there are a number of us that'd be happy to help.
If you have any questions or concerns, please shout out so I can help get them fixed for you.
[0] https://phabricator.wikimedia.org/T236132 [1] https://phabricator.wikimedia.org/T233012 [2] https://gerrit.wikimedia.org/r/c/integration/config/+/554110 [3] https://phabricator.wikimedia.org/project/view/1208/
Yours,