Bug#1012746: libwebkit2gtk-4.0-37: 2.36.3-1~deb11u1 fails messily over glx

[Markus Demleitner]

Given the publicity of some recent webkit bugs I start getting mildly
nervous about the outdated webkit on my box.  After the latest update
didn't improve things, I started poking a bit more, and it turns out
that the bug title was *very much* over-generalising.

The crashes very specifically occur on one screen of a two-screen
"ZaphodHeads" setup on nouveau.  It is actually the case that

DISPLAY=display-host:0.0 luakit

runs just fine, whereas

DISPLAY=display-host:0.1 luakit

shows the crashes.

I have to admit this badly stumps me.

I'm still reluctant to delve into either of webkit or nouveau, so...
does someone perhaps have a theory what might possibly cause such a
thing that I could try before I start digging?