NVIDIA Reverse PRIME Sync (and Xorg bug)

The Reverse PRIME on NVIDIA sync mode is a much anticipated feature for hybrid setups, like Intel/AMD+NVIDIA laptops. The good news — the implementation PR is already here, and it is functioning.

The bad news is some Xorg bug which makes it crash and dump core when changing external monitor settings. It needs testing, so I’m doing a signal boost thread here.

I’m asking for help with testing and (possibly) Xorg debugging for the bug which causes the crash. Advice for debugging Xorg in NixOS is welcome. The error also seemingly exists in 21.1.3 version, which is not in release yet, so unstable channel users and advice for pinning fresher Xorg version are much welcome.

UPD: I’ll leave “Reverse PRIME on Linux” thread link here, just in case.