enricobuehlerandClaude Fable 5
6617275387
Field triage (Nobara, Discord): the kde.md starter host.env told desktop users to set PUNKTFUNK_COMPOSITOR=kwin, which PINS the backend — detect() short-circuits and the capture-loss rebuild never re-detects — so a mid-stream switch to Game Mode killed the stream instead of following it. A follow-up hardcoded XDG_RUNTIME_DIR=/run/user/1000 anchor broke PipeWire for any non-1000 uid (pw audio connect: Creation failed). Revamp across every starter/example/reference: - Desktop starters (kde/gnome/hyprland/sway) shrink to PUNKTFUNK_VIDEO_SOURCE=virtual + an explicit warning that pinning disables session-following; forcing a backend is CI/appliance-only. - host.env.example: rewritten around auto-detection; anchors demoted to a commented ssh/cron-only block with the uid trap spelled out; the gamescope ATTACH/MANAGED knobs documented (previously missing); case-sensitivity called out. - packaging/bazzite/host.env + README: drop the uid-1000 anchors (a systemctl --user service inherits/derives them); README's stale PUNKTFUNK_COMPOSITOR=gamescope-era template synced to the real one. - packaging/kde/host.env: loud APPLIANCE-ONLY header (it pins on purpose). - configuration.md: session-anchors section inverted to "leave unset", compositor row states the pin consequence, case-sensitivity note. - troubleshooting.md: new "session fails right after editing host.env" section (case, wrong-uid anchors, stale pin, restart-to-apply). - gamescope.md/bazzite.md: attach/managed descriptions match current behavior (managed is the infra-detected default; attach re-modes a box-owned session to the client's resolution). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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title, description
| title | description |
|---|---|
| KDE Plasma (KWin) | Configure a punktfunk host for KDE — host.env, quirks, and a headless KWin session. |
Configure a punktfunk host on KDE Plasma. The host uses KDE's KWin compositor to create a per-client virtual display, captured zero-copy on NVIDIA. This page assumes the package is already installed — see Ubuntu, Fedora, Arch, or the Bazzite appliance.
New here? Read Security & Safe Use first — a streaming host is remote control of the machine, so keep it on a trusted LAN or VPN and require pairing.
host.env
The host auto-detects your KWin session on every connect — including a box that switches between
the Plasma desktop and Steam Game Mode — so the starter ~/.config/punktfunk/host.env is one line:
# ~/.config/punktfunk/host.env (keys are case-sensitive)
PUNKTFUNK_VIDEO_SOURCE=virtual
# GPU zero-copy (dmabuf → CUDA → NVENC) is ON by default; auto-falls back to CPU. Set =0 to force CPU.
Don't set
PUNKTFUNK_COMPOSITOR,WAYLAND_DISPLAY, orXDG_CURRENT_DESKTOPhere. Pinning the compositor turns auto-detection off — per connect and mid-stream — so a switch to Game Mode then kills the stream instead of being followed, and stale session values point the host at dead sockets. Forcing a backend is for CI and dedicated appliances (the headless session below ships ahost.env.kdethat pins on purpose).
If the box switches between the desktop and Game Mode, also enable lingering — the host is a user service, and without linger the logout moment of a session switch tears it (and PipeWire) down mid-stream:
sudo loginctl enable-linger "$USER"
See the Configuration reference for every option.
Use a Wayland session
KDE must run on Wayland, not X11 — pick the Wayland session from the picker on the login screen. The virtual-display path is Wayland-only and will not come up under X11.
KWin must be 6.5.6 or newer (virtual outputs land there). Check with:
kwin_wayland --version
Streaming the interactive desktop
To stream a logged-in Plasma desktop (rather than a headless session, below), KWin has to hand the
host its restricted screencast protocol. The host package ships an io.unom.Punktfunk.Host.desktop
file whose X-KDE-Wayland-Interfaces grants exactly that on a normal interactive session
(least-privilege, the same mechanism krfb/krdp use). After a fresh install, log out and back into
the Desktop session once so KWin re-reads the grant.
A normal KDE login still lacks the RemoteDesktop grant that input injection needs — without it the host pops an "Allow remote control?" dialog no headless box can answer. Fedora and Bazzite ship a one-shot helper that seeds it (run once as the streaming user, no root):
bash /usr/share/punktfunk/bazzite/kde-desktop-setup.sh # Fedora / Bazzite
The .deb and Arch packages don't include that wrapper. Seed the grant by hand instead — copy the
shipped kde-authorized file into the portal store (the share dir is /usr/share/punktfunk-host on
Debian/Ubuntu, /usr/share/punktfunk on Arch), then log out and back in:
mkdir -p ~/.local/share/flatpak/db
cp /usr/share/punktfunk*/headless/kde-authorized ~/.local/share/flatpak/db/kde-authorized
A login-less appliance skips all of this — its headless session (below) needs none of these grants.
Start the host
With host.env in place, start the host from inside your Plasma session:
systemctl --user enable --now punktfunk-host
journalctl --user -u punktfunk-host -f # watch it come up and print its identity fingerprint
Then bring up The Web Console to arm pairing and connect a client. To start at boot — including fully headless — see the headless session below or Running as a Service.
Persistent per-client scaling
KWin round-trips per-client display scale: it names each session's virtual output per client, so a scale you set for one client (150 %, 125 %, …) is reapplied on that client's next connect. See Virtual displays.
Headless session
For a login-less appliance — a box that streams at boot with no graphical login — the host brings up a
dedicated headless KWin session rather than relying on an interactive one. It runs its own
kwin --virtual session (shipped as the punktfunk-kde-session.service unit) with permission checks
relaxed, so it needs none of the interactive grants above.
mkdir -p ~/.config/punktfunk
cp /usr/share/punktfunk/host.env.kde ~/.config/punktfunk/host.env # Debian/Ubuntu: /usr/share/punktfunk-host/host.env.kde
systemctl --user daemon-reload
systemctl --user enable --now punktfunk-kde-session punktfunk-host
sudo loginctl enable-linger "$USER"
The session unit brings up headless KWin; the host unit follows it and starts listening. See Running as a Service for the full headless setup.
Troubleshooting
- KWin too old: virtual outputs need KWin ≥ 6.5.6. Check with
kwin_wayland --version. - Black screen / no picture: confirm you're on a Wayland session (not X11) and the NVIDIA GL userspace is installed. More in Troubleshooting.
To bring the console up and pair, see The Web Console.