o/
Firstly, I hope y'all are having good holidays.
Fortunately (or unfortunately), this browser test has picked up what looks
like a regression.
It's likely caused by the recent Multi-Content Revision work that was
merged into core on December, 21st ([0] onwards). The reason I point to
this code rather than the MobileFrontend extension or the Minerva skin is
that neither project had a change merged on that date (or the 20th) that
changed the way they interacted with the core Revision class.
AFAICT it only affects the Special:EditWatchlist page as the
Special:Watchlist (and others) are working fine. Just to confirm the
obvious, this is only affecting the Beta Cluster *right now*.
I'll comment on the change that introduced the regression (from our
perspective) [0] and submit a change that fixes it, and I'll review the
code backing Special:EditWatchlist to understand how a funky value might be
getting passed to a method on the Revision class. If there's a task for the
next deployment, then I'll comment that this should probably block it.
-Sam
[0]
https://github.com/wikimedia/mediawiki/commit/6af796f3e0cf3e66cd7d7e59af844…