/var/lib/ is in mediawiki-extensions-base 3.6.
This file is owned by root:root, with mode 0o755.
..
/var/lib/mediawiki/
/var/lib/mediawiki/extensions/
/var/lib/mediawiki/extensions/NewestPages
/var/lib/mediawiki/extensions/Interwiki
/var/lib/mediawiki/extensions/Cite
/var/lib/mediawiki/extensions/InputBox
/var/lib/mediawiki/extensions/NewUserNotif
/var/lib/mediawiki/extensions/CategoryTree
/var/lib/mediawiki/extensions/News
/var/lib/mediawiki/extensions/RSS_Reader
/var/lib/mediawiki/extensions/LanguageSelector
/var/lib/mediawiki/extensions/ImageMap
/var/lib/mediawiki/extensions/FootNote
/var/lib/mediawiki/extensions/PageCSS
/var/lib/mediawiki/extensions/Poem
/var/lib/mediawiki/extensions/CreateBox
/var/lib/mediawiki/extensions/Polyglot
/var/lib/mediawiki/extensions/TreeAndMenu