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>
9.6 KiB
title, description
| title | description |
|---|---|
| Troubleshooting | Common problems setting up or using a punktfunk host, and how to fix them. |
Another streaming host (Sunshine, Apollo, …) is installed
Punktfunk is a Moonlight-compatible host. So are Sunshine and its forks (Apollo,
Vibeshine, Vibepollo, LuminalShine, …). Running one of them at the same time as
Punktfunk is not supported: they bind the same GameStream ports (47984/47989 and
47998–48010, plus a web UI on 47990 that collides with Punktfunk's management API), advertise the
same _nvstream mDNS name, and often install a conflicting virtual-display driver. The result
is address already in use errors, pairing that silently fails, the wrong host answering a client,
and capture/display glitches.
-
Punktfunk warns about this automatically: the host logs it at startup (visible in the web console's Logs tab and the system tray tooltip), and the Windows installer warns before installing. To check on demand, run:
punktfunk-host detect-conflictsIt lists any conflicting host found (installed or running) and exits non-zero if there is one.
-
Fix: stop and uninstall the other host, then start Punktfunk — e.g. stop the service (
sudo systemctl disable --now sunshine/ on Windowssc stop SunshineService) and uninstall it. If you only want to try Punktfunk without removing the other host, at least make sure the other host is fully stopped first (they cannot both run at once).
The host isn't found on the network
- Make sure the host is actually running (
systemctl --user status punktfunk-host, or you see it listening in the terminal). - Host and client must be on the same network/subnet. Discovery uses mDNS, which doesn't cross routed subnets or most VPNs-without-multicast. As a fallback, add the host by IP address in your client.
- A firewall on the host can block it. The native protocol's control plane is a fixed UDP port,
9777 — open this one. The per-session data plane rides a separate, random UDP port and
usually needs no firewall rule (see Video is slow to start, or fails across
subnets for why, and the one case where opening it
helps). GameStream/Moonlight (only with
--gamestream) uses TCP 47984/47989/48010 + UDP 47998–48010 (video/FEC 47998, ENet control 47999, audio 48000) + mDNS UDP 5353. Allow those on the host's firewall.
Video is slow to start, or fails across subnets
The native data plane (the raw UDP that carries video, separate from the 9777 control plane) uses
a random, per-session UDP port — the host binds 0.0.0.0:0, then tells the client which port it
got during the connect handshake. There is no fixed data port.
Video flows host → client, but the client sends the first packet: a small hole-punch datagram to that port. This is deliberate. It lets the host learn the client's real (possibly NAT-translated) source address and stream back to it, so a session can cross a NAT or a stateful inter-VLAN firewall without a forwarded data port. What it means for a host firewall:
- Same LAN, no host firewall (or the port allowed): the punch arrives immediately and video starts at once. Nothing to configure.
- Same LAN, host firewall that denies inbound (ufw/nftables/firewalld default): the punch is dropped, so the host waits ~2.5 s, then falls back to the address the client reported and streams anyway — a stateful firewall admits the return traffic because the host sent first. Net effect: it works, but each session takes ~2.5 s longer to start. That slow start is the symptom of a data-plane rule you're missing.
- Across subnets / NAT: the same punch-then-fallback applies, as long as the host's outbound video can reach the client (the path's stateful firewall then admits the return). If the host itself is behind NAT reached only via a forwarded control port, the data path may not establish — this is the case a fixed, forwardable data port would solve.
To remove the ~2.5 s fallback delay, pin the data port with --data-port (or the
PUNKTFUNK_DATA_PORT env in host.env) and open exactly that one port. The host then binds that
fixed port, skips the punch-wait, and streams straight to the client — no timeout to pay:
punktfunk-host serve --data-port 9778 # or PUNKTFUNK_DATA_PORT=9778 in host.env
sudo ufw allow 9778/udp # open exactly that one port
Two caveats. A fixed data port serves one session at a time; a second concurrent session finds it
busy and transparently falls back to a random port + hole-punch (logged). And --data-port streams
to the client's reported address, so use it only where that address is reachable — a flat LAN, or a
port-forward that doesn't remap the client's source. Leave it off (the default) to keep the
NAT-crossing hole-punch. On a normal single-LAN setup you can also just leave the data port closed and
accept the one-time ~2.5 s punch-timeout, or not run a host firewall on a trusted LAN at all.
nvidia-smi says it can't communicate with the driver
- The NVIDIA kernel module didn't load. With Secure Boot enabled, enrol the module's signing key:
sudo mokutil --import /var/lib/shim-signed/mok/MOK.der, reboot, Enrol MOK at the blue screen (or disable Secure Boot). On Fedora, follow RPM Fusion's Secure Boot steps. - After a kernel update the module may need a rebuild — reinstall the driver package.
The desktop won't start, or "GPU … not supported by EGL"
The NVIDIA GL/EGL userspace is missing — the base driver package doesn't always include it.
- Ubuntu:
sudo apt install libnvidia-gl-<version>(matching your driver). - Confirm
/usr/share/glvnd/egl_vendor.d/10_nvidia.jsonexists andnvidia-drm modesetisY.
See GNOME for the GL/EGL userspace details.
Black screen / no picture, but the client connects
- You must be on a Wayland session, not X11 (check the login-screen session picker).
- KWin must be ≥ 6.5.6 (
kwin_wayland --version); GNOME ≥ 48; gamescope ≥ 3.16.22. See KDE for the KWin/Wayland requirement and gamescope for the gamescope one. - If
host.envsetsPUNKTFUNK_COMPOSITOR, remove it — the host auto-detects the live compositor, and the pin points it at one backend even when a different session is live (it also disables Gaming ↔ Desktop following).
Session fails right after editing host.env
- Keys are case-sensitive:
punktfunk_gamescope_attach=1sets nothing — use the exact uppercase names. - Hardcoded session anchors with the wrong uid (
XDG_RUNTIME_DIR=/run/user/1000whenid -uisn't 1000) point the host at another user's PipeWire/D-Bus: audio errors likepw audio connect … Creation failed, no capture, and clients reporting the host as unreachable or asleep. Delete both anchor lines — asystemctl --userservice doesn't need them — or fix the uid. PUNKTFUNK_COMPOSITORpins the backend and disables Gaming ↔ Desktop following — remove it on any box that switches sessions.- The env file is read at service start:
systemctl --user restart punktfunk-hostafter edits.
Capture fails: "Session creation inhibited" (GNOME)
A locked GNOME session blocks screen capture. On an always-on/headless host, disable the lock:
gsettings set org.gnome.desktop.screensaver lock-enabled false
gsettings set org.gnome.desktop.session idle-delay 0
See GNOME → Headless session and Running as a Service.
A controller is detected but does nothing (Bazzite)
The host user needs to be in the input group. On Bazzite:
ujust add-user-to-input-group
Then log out and back in. On other distros this is sudo usermod -aG input $USER + re-login. See
Bazzite.
Pairing is rejected / the client can't connect
- The host requires pairing by default. Arm pairing from the web console, then enter the PIN on the client. See Pairing & Trust.
- If you re-installed the host, its identity changed — re-pair the client.
Stutter, drops, or high latency
- Lower the bitrate. On a busy or Wi-Fi link, the requested bitrate may be too high — the native clients' speed test picks a safe value; with Moonlight, set it manually.
- Prefer a wired connection or 5 GHz Wi-Fi between host and client.
- Streaming to many devices at once shares the GPU encoder. The host serves several concurrent native sessions (up to 4 by default); heavy load is usually bitrate-bound, so lower the bitrate first.
Windows: "punktfunk Virtual Display" shows Code 10 in Device Manager
Sessions end with "pf-vdisplay driver interface not found" and Device Manager shows the
punktfunk Virtual Display device failed with Code 10 (STATUS_DEVICE_POWER_FAILURE).
This means your Windows version is too old. The virtual-display driver requires the IddCx 1.10 driver framework, which first shipped in Windows 11 22H2 (build 22621) — on Windows 10 (including LTSC) and Windows 11 21H2 the driver installs but cannot start. Reinstalling won't help; the fix is updating to Windows 11 22H2 or newer. (Current installers refuse to run on older Windows for this reason; if you see this, the host was likely installed with an older installer.)
Still stuck?
Run the host with RUST_LOG=info (or debug) and check journalctl --user -u punktfunk-host for the
error around the failed connect or capture.