60-punktfunk.rules chgrp's the usbip vhci attach/detach nodes to a dedicated
`punktfunk` group (security-review 2026-08-05 M-4: writing `attach` materialises
an arbitrary emulated USB device, so it must not ride on `input`). Four of the
six install paths shipped that rule in 0.25.0 without ever creating the group.
chgrp then failed, the nodes stayed root:root 0644, and the virtual Steam Deck
pad silently never attached — while `usermod -aG punktfunk` failed outright with
"group 'punktfunk' does not exist".
Affected and fixed:
* arch — post_upgrade() called only _ensure_update_group, so every box that
reached 0.25.0 by `pacman -Syu` missed it; post_install was correct.
* nix — no users.groups.punktfunk at all, though host.users' own description
already promised the usbip/vhci pad. Declares it now and adds
host.users to both groups.
* bazzite sysext — a group is host state and cannot ride an image, and the
deb/rpm scriptlets that would create it never run there.
* steamdeck install.sh/update.sh — handled `input` only. Both now create the
group and join it: running that script IS the statement "make my
Deck a host with native pad passthrough".
deb and rpm were correct throughout (one postinst/%post for install + upgrade).
Also on the Deck path: web.env secret hygiene. install.sh's `chmod 600` sat
inside the create-only branch despite a comment calling it "the idempotent belt
for a pre-existing file", and update.sh never touched the config dir at all — so
an install set up once and only updated since kept web.env world-readable
(0644) with the console password and session secret in it. Both scripts now
harden ~/.config/punktfunk to 0700 and web.env to 0600 on every run, and say so
loudly, because a chmod does not un-leak an already-readable secret: the
password still needs rotating.
Both group blocks are `if ensure_group ...` rather than `ensure_group || true`:
a failed groupadd must not fall through to a usermod against a nonexistent
group, which under `set -e` aborted install.sh after the long build and
update.sh before the service restart (verified: exit 6, no restart).
Docs: the group is now documented where people actually look — the per-distro
guides, install.md, steamos-host.md, a new troubleshooting entry for "pad
arrives as an Xbox 360 controller", and the uninstall pages. The 0.25.0 notes
gain the "group does not exist" caveat and turn the password bullet from
"consider rotating" into a real instruction, and CHANGELOG records the known
issue against the breaking change that introduced it.
Verified: bash -n on all four scripts; the arch scriptlet's post_upgrade driven
in a container (creates the group, idempotent on re-run); the ensure_group
helper and both membership branches, including a control that reproduces the
original bug (chgrp to a missing group leaves the node root:root 0644); the
find -perm /0077 probe across 0644/0640/0604/0600/0400 on GNU findutils;
`nix flake check --no-build` (the exact CI gate) and a NixOS eval showing
alice.extraGroups == ["input","punktfunk"]; docs-site build + typecheck.
Field report (RX 5700 / SteamOS): 10-bit HEVC "unsupported" — but the GPU was
never the blocker (RADV probed Main10 fine on that box). The session stayed SDR
because stock gamescope offers no 10-bit PQ capture formats and nothing shipped
our pipewire-hdr build outside the Bazzite sysext, while PUNKTFUNK_GAMESCOPE_HDR
additionally defaulted off everywhere. Close all three gaps:
- PUNKTFUNK_GAMESCOPE_HDR now defaults ON (explicit-off grammar, the flip the
config comment planned post-canary). Safe by construction: the +pfhdr banner
probe, managed-spawn term, and client 10-bit cap keep stock-gamescope boxes on
the exact 8-bit path. The nix module's gamescopeHdr (default true now) only
controls whether the patched binary is on PATH; it no longer sets the env.
- SteamOS: new scripts/steamdeck/build-gamescope.sh builds the HDR gamescope in
the same pf2 trixie distrobox (apt dep list validated by a full build in a
debian:trixie container), installs ~/.local/bin/punktfunk-gamescope, and
maintains PUNKTFUNK_GAMESCOPE_BIN in host.env ONLY while the binary passes its
on-glass --version/+pfhdr check — a stale absolute override would break
session spawning, not just HDR. Wired into install.sh (§3b), update.sh
(retrofit), and rebuild-check.sh (ldd-probes it like the host binary).
- Arch: build-sysext.sh gains a --gamescope fold-in (banner-verified by
execution, host-image-only), and punktfunk-host optdepends the companion.
Deliberately NO CI-published host sysext: per the 2026-07-22 packaging
verdict a prebuilt SteamOS host breaks on A/B soname bumps (and /var is
per-partition-set), so arch.yml records that instead — SteamOS hosts use the
distrobox flow above.
Also fixes a latent bug that made build-sysext.sh fail every invocation as
documented: a literal `}` inside `${1:?usage …{host,client}…}` terminates the
expansion early and corrupts $PKG (caught by the new synthetic-package test,
which also covers the fold-in, the unmarked-gamescope refusal, and the
client-image guard).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
- rebuild-check.sh + punktfunk-rebuild-check.service (enabled, ordered
Before=punktfunk-host): ldd-probes the host binary at session start —
milliseconds when healthy, a full update.sh rebuild only when a
SteamOS update actually broke its library links. update.sh restarts
go --no-block so the check → update.sh → restart chain can't deadlock
against the unit ordering. update.sh retrofits the unit.
- installer summary: web console is https (the unit serves TLS).
- docs: steamos-host.md (runner in the build step, keep-list + auto
rebuild = updates survive hands-free), gamescope.md (Gaming Mode
touch = single-finger pointer, exact taps, no multi-touch),
plugins.mdx (SteamOS runner note), scripts/steamdeck/README.md
(rebuild-check, runner payload, keep list, honest packaging
trade-off + the CI-prebuilt future direction).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Verified live on a SteamOS 3.8.14→3.8.16 update: the A/B partset switch
rebuilds /etc and drops everything not on Valve's keep list — the udev
rule (uhid access: virtual pads silently degrade to Xbox 360), the
vhci-hcd autoload (native Deck pad transport), and the UDP buffer sysctl
(back to 208 KB → stutter). Valve's sanctioned extension point is a
drop-in under /etc/atomic-update.conf.d/ — itself on the stock keep
list, so it self-preserves. install.sh §4 and update.sh now register
scripts/punktfunk-atomic-keep.conf there.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
- scripts/steamdeck/install.sh (§2b) + update.sh: build and install the
scripting runner user-scoped (~/.local wrapper + pinned bun + bundle) —
SteamOS's read-only /usr can't take the .deb layout, so the console's
plugin store reported "the plugin runner isn't installed" on every
SteamOS host. update.sh retrofits it onto existing installs.
- plugins.rs runner discovery: check the ~/.local layout after the /usr
ones; mention the SteamOS path in the not-installed error.
- update.sh: define warn() — it was used but never defined, so under
`set -e` the first warn aborted the update before services restarted.
- pf-client-core gamepad: a Steam Input virtual pad forwarded on a real
Deck (the only-pad case) now declares the DECK kind in its per-pad
arrival instead of the wrapper's Xbox 360 identity — the session-level
auto_pref already resolved SteamDeck, but the arrival overrides it on
current hosts.
- reject tests: cover SetupFailed; move the foreign-code probe off 0x68.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The system-tuning block (UDP buffers, gamepad udev rule, vhci-hcd autoload,
input group) was gated on `sudo -n true` — passwordless sudo — so on a stock
SteamOS box (the deck account needs a password) the whole block was silently
skipped: /dev/uhid stayed root-only so the gamepad degraded to an Xbox 360 pad,
and the UDP buffers stayed at the 416 KB default. Video was unaffected because
Game Mode/gamescope needs none of it, which masked the skip on-glass.
- install.sh + update.sh: acquire sudo interactively (`sudo -v` prompt on a TTY)
instead of requiring passwordless; skip only when there's no TTY or auth fails,
and then print the exact manual block plus a `passwd` hint — a stock SteamOS
'deck' account has no password, so sudo can't work until one is set.
- update.sh: also retrofit the UDP-buffer sysctl for older/skipped installs, and
loudly nag to reboot when the input group was just added (a --user restart does
not pick up the new group; only a fresh login does).
- steamos-host.md: note this step prompts for the sudo password.
Root is unavoidable: the udev rule, input group, and vhci-hcd module are all
kernel operations with no user-space alternative.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
A fresh SteamOS host install failed on-glass two ways: KWin denied Desktop-mode
capture (zkde_screencast_unstable_v1) so every session died in the pipeline build,
and the native Steam Deck pad degraded to an Xbox 360 controller. Both stem from
setup that only a fresh login applies — the host user-service keeps the
pre-install group set and KWin reads its .desktop grant at session start — plus a
missing vhci-hcd autoload the pad's USB/IP transport needs (the deb/rpm/arch
packages ship it; the Deck installer did not).
- install.sh: install punktfunk-modules.conf (+ modprobe vhci-hcd now) for the
native Deck controller transport, seed the KDE RemoteDesktop grant
(kde-authorized) for Desktop-mode input, and print a loud "reboot before
streaming" notice when a relogin is actually required (input group added or the
.desktop grant first installed).
- update.sh: retrofit the udev rule, vhci-hcd autoload, input group, and grant so
existing installs pick them up on the next update without a reinstall.
- steamos-host.md: document the first-install reboot and the native controller
passthrough requirements (input group + vhci-hcd + client-side Steam Input Off).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The SteamOS scripts built the host featureless, so PlatformAuto could never
pick the Vulkan Video backend (default-on since 84329205) and every session
silently ran libav VAAPI — unlike the deb/arch/rpm/sysext builds, which all
pass the feature. Three gaps, found live on a Deck host:
- install.sh/update.sh: cargo build with --features punktfunk-host/vulkan-encode
(matches the packaged builds; pure-Rust ash, no new system dep).
- host.env: RADV_PERFTEST=video_encode — Van Gogh RADV still gates
VK_KHR_video_encode_* behind it, so without it the backend can't open and
falls back to VAAPI. Harmless where encode is exposed by default.
- io.unom.Punktfunk.Host.desktop (Exec rewritten to this install's binary):
KWin only grants zkde_screencast_unstable_v1/org_kde_kwin_fake_input to an
exe a .desktop authorizes — without it Desktop-Mode capture fails outright
and a mid-stream Game↔Desktop switch strands the stream on the old backend.
update.sh retrofits the last two idempotently so existing installs get them
without a reinstall.
Validated on a SteamOS 3.8.14 Deck (Van Gogh): Vulkan HEVC opened on both the
KWin and gamescope paths at 5120x1440 — in-place ABR reconfigure (no IDR, no
encoder rebuild) vs the VAAPI path's full teardown per ABR step, and Desktop
capture came up without a re-login.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
SteamOS is immutable read-only Arch, and the Deck is AMD (VAAPI) — so none of the
checked-in packaging (arch/sysext is NVENC-first + client-oriented, deb/rpm are
soname-mismatched) actually installs a working host on a Steam Deck. The proven path
(distrobox-built native binary + systemd-run units) was 100% manual. Make it one command.
- scripts/steamdeck/install.sh — idempotent installer: ensure the pf2 Debian-trixie
distrobox + toolchain → build host (+web console) → write config (generated web login
password) → raise UDP buffers to 32 MB + udev + input group (sudo, skipped gracefully
if unavailable) → install + start punktfunk-host / punktfunk-web systemd USER services
with linger. Flags: --open (accept unpaired clients), --no-web, --src=DIR. Builds
on-device so a rebuild always matches the running SteamOS (no prebuilt-binary fragility
across OS updates); VAAPI on the Deck's AMD GPU.
- scripts/steamdeck/update.sh — rebuild from current source + restart (config/pairings persist).
- scripts/steamdeck/README.md — deep reference (why on-device, what's installed, gotchas).
- docs-site: new "Steam Deck (Host)" guide + sidebar entry; install.md splits Arch from the
Steam Deck host path; packaging/arch/README points Deck-host users here and corrects the
stale "NVENC-only" note (VAAPI host encode landed).
Live-validated on the Deck: installer runs clean, both services come up, host listens
(QUIC :9777 + mgmt :47990), web serves (302→login); on a client connect it takes over the
Game-Mode gamescope session at the client's mode, captures via PipeWire, and VAAPI-encodes
(hevc_vaapi) — full pipeline confirmed in the host journal.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
