So we removed deprecated stuff from MW core, Yay. But we still use old Semantic extension branches
I added https://gerrit.wikimedia.org/r/#/c/264023/ as a possible fix
I can't say I want to have that merged, but we either need something like that, or we also backport/make the wfMsg* fixes to the old branches
Then the newer branches are out of sync...
It's a mess
Or we just undeploy it all