https://doc.wikimedia.org/cover/mediawiki-core/master/php/ is 404. This link appears in Manual:PHP unit testing. Maybe the manual is outdated?
Topic on Project:Support desk
https://doc.wikimedia.org/cover/mediawiki-core showing me 403 Forbidden. Before 30 minutes it worked without problems.
Maybe someone doing something in the server.
I same think it.
Well, you're missing the last slash: https://doc.wikimedia.org/cover/mediawiki-core/
Interesting. But https://doc.wikimedia.org/cover/mediawiki-core/master/php/ still 404.
Maybe they changed the software that displays that page, and now the URL structure is different