maintainer-feedback requested: [Bug 273369] x11-servers/xorg-server: "Cannot run in framebuffer mode" after updating to 21.1.8_4,1

From: <bugzilla-noreply_at_freebsd.org>
Date: Sat, 26 Aug 2023 20:32:29 UTC
Bugzilla Automation <bugzilla@FreeBSD.org> has asked freebsd-x11 (Nobody)
<x11@FreeBSD.org> for maintainer-feedback:
Bug 273369: x11-servers/xorg-server: "Cannot run in framebuffer mode" after
updating to 21.1.8_4,1
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=273369



--- Description ---
After updating all packages on an existing (working) 13-stable system, startx
fails with "Cannot run in framebuffer mode. Please specify busIDs for all
framebuffer devices".  Rolling back just xorg-server to the previous installed
version (21.1.8,1) from /var/cache/pkg fixes the problem.

I'm not absolutely certain, but I suspect https://reviews.freebsd.org/D39886
may be the culprit, as it appears to be the only non-trivial changes that could
affect my (amdgpu) configuration between the working and failing xorg-server
versions.

Attaching dmesg and Xorg.0.log for the working and failing cases.