AltTab does not close when I select Quit or Force Quit from Activity Monitor

[imfromthenet]

Describe the bug
I have been having the unwanted behaviour of AltTab not showing some of open programs. To try to remedy this, I wanted to restart AltTab. To do that I started Activity Monitor, found AltTab. Selected it, pressed on X button and then selected Quit. nothing happened. then I tried Force Quit. The result was the same.

I would expect that AltTab would be easy to quit.

Screenshots / video

Screen.Recording.2022-02-07.at.12.49.36.mov

Steps to reproduce the bug

1. Go to 'Activity Monitor'
2. Click on 'AltTab'
3. Click 'X'
4. Select 'Quit'

[lwouis]

You can quit AltTab from the app icon in the menubar at the top of the screen. That's the intended way to quit it.

Now of course Activity Monitor should work as well.

I tried to launch AltTab, and quit it and force-quit it through Activity Monitor, and both cases worked correctly. So I can't reproduce the issue that you show in the video. I'm not sure what's different about your setup.

Something to note in your video is that AltTab is indeed quit when you ask for it. However, it's immediately re-launched. You can see the PID on the right changing, and the CPU counter being blank for a few seconds.

I'm thinking that it could be due to the following thing:

Back in November 2021, we moved from one way to implement "Start at login", to another implementation (664c5b9). The new way relies on Launchd, and has this line here: 664c5b9#diff-323d91ad380ecd3f3fc161764535c247cf088a79fc2aba547e6e2f64fb146adaR50

It may be that this line being true makes Launchd restart the app after a force-quit? I can't explain why it would do it after a normal Quit though? Also why doesn't it happen on my machine? It could be that I manually quit and start AltTab, from which point it's now manually launched and not supervised/relaunched by Launchd if it terminates.

This doc here explain the dangers of KeepAlive. However, we use it with SuccessfulExit, as they recommend, so it should be fine, and actually only relaunch AltTab on crashes, which is a behavior what we want for users to have a smooth experience.

[kylemart]

I'm experiencing a similar issue to OP. After updating to the macOS Monterey 12.3 beta, I started running into persistent crashes. Immediately after choosing "Don't send" or "Send", it fires back up again and immediately crashes. Tried terminating AltTab with the Activity Monitor and kill command, but neither worked.

[lwouis]

@kylemart regarding macOS beta please see #1351. Regarding the auto-restarts, please see my comment above. You may want to play with Launchd to see if my hypothesis is correct. In which case maybe it's best to disable this keepalive, even though we would lose the upside of actual crashes being mitigated