John SiracusaSep 27, 2023

Oh noooooo! FB12122106 still exists in macOS 14.0 (23A344)

https://mastodon.social/@siracusa/110117776662224597

https://youtu.be/h0bKmcsMFvw

I wasn’t able to reproduce it in a clean install of Sonoma, so it's obviously something related to my specific configuration. But damned if I know what it is…

FB12122106 Demonstration

YouTube
Show threadJohn SiracusaSep 27, 2023

Still trying to track down this bug https://mastodon.social/@siracusa/110255326994000695

To review:

1. It happens only when more than one user is logged in.

2. It does not happen on a clean install of Sonoma—but it does happen on my actual install of Sonoma.

3. It happens even when the only two users logged in are two newly created user accounts.

4. No non-Apple KEXTs are installed.

Given all of this, I've been looking in /Library for culprits. Is there some other place I should be looking?

Show threadTodd Thomas Sep 27, 2023
@siracusa what if you ran ‘sudo spindump windowserver -heavy’ while you are making the window stutter on the machine and see if that gives you any possible clues. Just guessing it could have something to do with two window server instances running (I'm assuming the other person is logged in and you are fast user switching between the two?)
Show threadJohn Siracusa
@todd Yes, both users are logged in. The spindumps for the bug and normal case are both baffling to me.
Sep 28, 2023 at 12:06amIvory for iOS
Show threadDennis WilkinsonSep 28, 2023

@siracusa @todd Is the other user logged in but idle (i.e no one has a Remote Desktop session actually exercising things?)

Same display scaling for both users?

I might diff the filesystem under /Library on symptomatic and asymptomatic installs, but that's going to have a lot of noise.

Show threadDennis WilkinsonSep 28, 2023
@siracusa @todd Also, is there anything spitting to Console?
Show threadJohn SiracusaSep 28, 2023
@djwtwo There’s always a ton in the Console, but nothing stands out so far.
Show threadJohn SiracusaSep 28, 2023
@djwtwo Yes, idle. Same display settings. I’m already well into diffing /Library with a clean install. No luck yet.
Show threadDennis WilkinsonSep 28, 2023

@siracusa I just gave it a try on my multiuser 13.5.2 box (M1 Ultra Studio with 64GB), which is an increasingly-crufty installation (migrated from a 2012 Mac Pro.) Couldn't repro, even with >128 windows open. Fg user was admin, bg was normal; no idea if that would matter.

If nothing else, if you see something suspicious, I could double-check against that install to see if I have the suspicious item.

Show threadTodd Thomas Sep 28, 2023
@siracusa they might be useful to someone inside Apple?