otsukare Thoughts after a day of work

Capping User Agent String - followup meeting

Web compatibility is about dealing with a constantly evolving biotope where things die slowly. And even when they disappear, they have contributed to the balance of the ecosystem and modified it in a way they keep their existence.

Ginko Dead leaves

A couple of weeks ago, I mentionned the steps which have been taken about capping the User Agent String on macOS 11 for Web compatibility issues. Since then, Mozilla and Google organized a meeting to discuss the status and the issues related to this effort. We invited Apple but probably too late to find someone who could participate to the meeting (my bad). The minutes of the meeting are publicly accessible.

Meeting Summary

Some additional news since the meeting

To comment…

Archived copy of the minutes

This is to preserve a copy of the minutes in case they are being defaced or changed.

Capping UA string
(Minutes will be public)

Present: Mike Taylor (Google), Karl Dubost (Mozilla), Chris Peterson (Mozilla), Aaron Tagliaboschi (Mozilla), Kenneth Russell (Google), Avi Drissman (Google), Tantek Çelik (Mozilla)

### Background

* Karls summary/history of the issue so far on

* What Apple/Safari currently does
Safari caps the UA string to 10.15.7.

* What is Mozilla status so far
Capped UAs macOS version at 10.15 in Firefox 87 and soon ESR 78:

Capped Windows version to 10 (so we can control when and how we bump Firefox's Windows OS version if Microsoft ever bumps Windows's version):

### What is Google status so far

Ken: We have 3 LGTMs on blink-dev, but some folks had concerns. We know there's broad breakage because of this issue. It's not just Unity, and it's spread across a lot of other sites. I think we should land this. Apple has already made this change. Our CL is ready to land.
Avi: I have no specific concerns. It aligns with our future goals. It is unfortunate it brings us ahead of our understood schedule.
Mike: Moz is on board. Google seems to be on board.
Kenneth: If there are any objections from the Chromium side, there has been plenty of time to react.
Mike: Have there any breakage reports for Mozilla after landing?
Karl: Not yet. I've seen a lot of reports related to Cloudinary, etc, which are a larger concern for Apple. For Firefox, there was no breakage with regards to the thing that was released last week. It's not yet in release. There's still plenty of time to back it out if needed.
Chris: Was there an issue for Duo Mobile?
Karl: We didn't have any reports like this. But we saw a mention online... from what I understood. Apple had modified the UA string to be 10.15. Then the OS evolved to 10.16. Duo had an issue with the disparity between 10.15.7 in the OS and 10.15.6 in the browser. Since then, they modifed and there's no other issue.
Karl: On the Firefox side, if we have breakage, we still have possibility to do site-specific UA interventions.
Ken: did you (tantek) have concerns about this change? The review sat there for a while.
Tantek: I didn't have any problems with the freezing MacOS version per the comments in our bugzilla on that. My general philosophy is that the UA string has been abused for so long, freezing any part of it is a win. I don't even think we need a 1:1 replacement for everything that's in there today.
Chris: The long review time was unrelated to reservations, we were sorting out ownership of the module.

### macOS 11.0 compat issues:
Unitys UA parsing issue
Cloudinarys Safari WebP issue
Firefox and Chrome send Accept: image/webp header.

### Recurring sync on UA Reduction efforts
Which public arena should we have this discussion?

Mike: we do have public plans for UA reduction/freezing. These might evolve. It would be cool to be able to meet in the future with other vendors and discuss about the options.
Chris & Karl: Usual standards forums would be good. People have opinions on venues.