Change 709235 had a related patch set uploaded (by Zabe; author: Zabe):

[operations/mediawiki-config@master] Enable SUL autologin for wikimania.wikimedia.org

https://gerrit.wikimedia.org/r/709235

Change 709235 merged by jenkins-bot:

[operations/mediawiki-config@master] Enable SUL autologin for wikimania.wikimedia.org

https://gerrit.wikimedia.org/r/709235

Mentioned in SAL (#wikimedia-operations) [2021-08-02T18:33:53Z] <urbanecm@deploy1002> Synchronized wmf-config/InitialiseSettings.php: eec997cf88437fc6e2e27a835301aef968c548c4: Enable SUL autologin for wikimania.wikimedia.org (T285197) (duration: 00m 55s)

So, I synced this patch per @Zabe's request. However, I tried to autolog in to wikimania.wikimedia.org before the deployment (using my WMF staff account, as the volunteer acc was already logged in, and also in inkognito window with a test acc), and it _worked_. Are we sure it's not just enabled everywhere? cc @Legoktm.

Ummm, well it didn't work when I filed this task. I can't explain why it would've worked, unless I missed some change to SUL.

In any case, I logged into Meta just now (using private browsing) and it made the following requests:

https://wikimania.wikimedia.org/wiki/Special:CentralAutoLogin/createSession?token=[redacted]&type=1x1&from=metawiki&proto=https
https://login.wikimedia.org/wiki/Special:CentralAutoLogin/validateSession?token=[redacted]&wikiid=wikimaniawiki&type=1x1&from=metawiki&proto=https
https://wikimania.wikimedia.org/wiki/Special:CentralAutoLogin/setCookies?type=1x1&from=metawiki&proto=https

Then I went to wikimania.wikimedia.org and it popped up the "You've been centrally logged in, please refresh the page" bubble notification and I was logged in (I thought I would already be logged in without the need for refresh but meh).

Resolved?