SteamOS NVIDIA Installer 0.2.1

This release delivers a filter that stops Steam being offered display modes the compositor will
reject, a clearer Gamescope section in the diagnostic report, and a repair path in Installer Update
for a system that already reports this version but is missing files from it.

Five files differ from 0.2.0: the Gamescope build, its provenance record, the updater, the updater's
window, and the diagnostic report. Every other file in the signed bundle is byte identical to 0.2.0.

What the display mode filter changes

A 4K television that offers 4096x2160 could have that mode written into Steam's saved preference. The
compositor rejects it, and because no match is found the screen comes up at a lower resolution with no
message explaining why. This build stops that mode being advertised, so it cannot be chosen by
accident. On the television this was tested with, the advertised list went from seven modes including
four at 4096x2160 to three, all at 3840x2160.

A system that already has 4096x2160 saved will still start at the lower resolution until the
resolution is chosen once by hand.

Gamescope compatibility, and where the corrections are active

The bundled Gamescope build carries four corrections: two capture fixes adapted from upstream work, a
correction for the corrupted Game Mode menus on NVIDIA, and the display mode filter above.

The two capture fixes are present in upstream Gamescope 3.16.30. The menu correction and the mode
filter are not, so a system running the distribution's own compositor does not have them.

This project's build is selected only where the system is on the SteamOS 3.8 line, ships
gamescope 3.16.23.6-1, and has the session layout the build expects. On a system outside those
conditions, including the SteamOS 3.9 line, this release leaves the distribution's compositor in
use, and these two corrections are then inactive. The integration was tested surviving an OS update
to 3.9.2 and back; applying Installer Update while already on 3.9.2 was not tested. Read the
recorded decision at any time:

cat /usr/lib/steamos-nvidia/gamescope/status.txt

A line beginning stock means this project's build is not in use. On the 3.9.2 system this was tested
on, the menu corruption returned in that state.

The SteamOS versions named in the signed manifest record where the integration was tested, which is not
the same thing as a guarantee that every optional correction is active. Applying a release on the 3.9
line in particular has not been exercised.

Known limitations

Gamescope can crash while leaving Game Mode. Two separate failures were seen on the test machine:
a fault in the Vulkan cleanup at exit, which was also seen on 0.2.0 and on the distribution's own
packaged build, and a separate abort when the X11 connection goes away during shutdown. Both happen as
the session ends. Desktop startup and re-entry to Game Mode were observed after both kinds of exit,
and a game was also run after the Vulkan cleanup failure. Neither is fixed by this release, and neither is
claimed to be harmless: each one writes a core dump, which takes disk space. The Vulkan one is reported
upstream as ValveSoftware/gamescope#1526.

Raising the output resolution while Game Mode is already running can corrupt the picture until the
session is restarted. This release does not fix that and does not establish where the fault belongs.
Restarting Game Mode is what clears it. Choosing the resolution before you start playing is a
sensible precaution rather than a tested remedy.

Verifying what you downloaded

installer-bundle.tar      b71564006d21ffbc2a31b71efefb15623b134b3b756d47ac7ad3857734ed7d25
installer-manifest.json   9030162ccf3a4ea0fc0eda82d00bff0da9130ea3b3f328a2bff0682db42a13ba

installer-manifest.sig is an Ed25519 signature over the manifest, made with the key an installed
system already carries, so Installer Update verifies both the manifest and every file in the bundle
before anything is written. The manifest's own bundle_sha256 must match the bundle, and it does.

These three files are for Installer Update. They are not source archives and not bootable images. To
build an installer image, follow
Build the USB image.

The wiki is the current manual. The source archives on this page are a snapshot of the code at this
tag, so a documentation page inside them can be older than the same page on the wiki.

How it was tested

On one PC, an RTX 5060 with the pinned NVIDIA 610.57.04 driver, on SteamOS 3.8.28 build 20260922.1.
Three routes, each including the machine taking its first SteamOS update afterwards: a clean
installation from the image, an update from the desktop over an existing 0.2.0 system, and an upgrade
from the USB image over an existing installation. In every case the integration survived the OS update
with all of its recorded files intact, and the compositor this project builds was confirmed to be the
one running, by resolving the live process rather than by appearance.

One machine is one machine. Another display, another connection or another pair of display modes should
be treated as untested rather than as known good.