XQuartz crashes on Mac Studio after upgrading to Sonoma

Thanks for your response. I mean the OS crashes completely in full panic mode shortly after I try to boot XQuartz, and then the machine reboots itself, with chime. See reply to VikingOSX for more details.

Thanks for your response. I wound up talking to a helpful AppleCare person, who suspected the problem lay within XQuartz, since none of my other apps were giving me problems. He suggested I try XQ with a new, "clean" login to test this idea, and he was right. The clean user could boot XQ with no problem.

This meant it was something in my personal XQ environment. I spent the next day looking at various pieces, and eventually zoomed in on the customisations in my ~/.xinitrc file. (This was something I had added to over the years, through several prior versions of XQ well before 2.8.2, and also several prior OSX incarnations going back to Tiger, at least.) Still, when I moved this file elsewhere and tried booting up XQ, it worked fine in my own login. I discovered that the system-default file (in /opt/X11/etc/X11/xinit/xinitrc) kicked in upon starting XQ, and I examined the differences between that and my .xinitrc file. There were very few; the only meaningful one was that the system default starts up the twm window manager (in /opt/X11/bin/twm) instead of the quartz-wm WM (in that same directory), which is what I had been using for years as above. My understanding was that twm was older and deprecated. Apparently not!

However, by this time I was anxious to get back up and running, so I didn't try any further experiments with WMs, and can't say whether the quartz-wm itself was the problem. Rather than try to reinvent the wheel, I left my .xinitrc file in its non-functional state, and arranged to invoke my X11 customisations in a more harmless way, ie, *after* XQ startup, as a simple c-shell command.

At any rate, I now have a functioning X11 system (with XQ 2.8.2) and everything that depends on it works fine again, in Sonoma. Some other points in response to your suggestions:

I did also try XQ 2.8.5 (the latest version), although as you say, no version of XQ has been "officially" released for Sonoma. But this failed as utterly as 2.8.2, so the XQ version wasn't the problem, as I explained above. I am also disinclined to muck around further with any upgrades: getting a working X11 environment back was critical for my work progress, so "removing XQuartz" would have been disastrous (sorry!).

Anyway, I do plan to contact the XQ team and relay the above saga. Thanks again for your comments and suggestions, I appreciate the effort!

PS: The fact that I had a working version of XQ with Monterey, with all customisations and any other warts present in their full glory, but that this very same setup caused the Mac OS to crash when running under Sonoma, does mean that some default action (either of the OS or of XQ) was no longer compatible with my existing setup. So, this problem was not *entirely* of my making!