Is it possible to tell Xorg not to listen on the abstract socket

I found the answer while I was writing the question, so I might as well post both in case that's some help to someone.

X -nolisten abstract

is accepted but doesn't work.

X -nolisten local

seems to work. I would have expected that one to disable all Unix domain sockets, but it doesn't. It disables the abstract namespace one only.

As noted by @imz--IvanZakharyaschev, and as confirmed by reading the code (https://cgit.freedesktop.org/xorg/lib/libxtrans/tree/Xtrans.c?id=c4262efc9688e495261d8b23a12f956ab38e006f#n99 -> https://cgit.freedesktop.org/xorg/lib/libxtrans/tree/Xtranssock.c?id=c4262efc9688e495261d8b23a12f956ab38e006f#n2532), to disable Unix-domain sockets, it's -nolisten unix.

In addition to the already given answer. If you want to apply this change to your system, consider looking at these files:

For plain "xinit": /etc/X11/xinit/xserverrc:

#!/bin/sh

exec /usr/bin/X -nolisten tcp -nolisten local "$@"

For "lightdm": /etc/lightdm/lightdm.conf.d/50-X-no-listen.conf

[Seat:*]
xserver-command=X -nolisten tcp -nolisten local

All credits go to this blog post: https://tstarling.com/blog/2016/06/x11-security-isolation/ (Thanks a lot for it!)