This week's 1.42.0-wmf.20 version of MediaWiki is blocked[0], and 1.42.0-wmf.19 may require a Monday rollback, which is a situation we hope to avoid.

We can't proceed until the following issue is resolved:

* T336504 - Transcluding Special:Prefixindex can force the default skin - https://phabricator.wikimedia.org/T336504

For context, see the Village pump discussion linked here:

* https://phabricator.wikimedia.org/T336504#9572477

Once this issue is resolved, the train can proceed normally for the week.

Thank you for any help!

-- Your designated sacrificial train victims

[0]. https://phabricator.wikimedia.org/T354438