Deep dive into the two GNOME-only host bugs (KWin/gamescope clean):
1. Stale-frame flashes (windows at old positions, typed text reverting):
Mutter renders its virtual monitors DIRECTLY into the PipeWire buffer
pool, and NVIDIA has no implicit dmabuf fencing — our zero-copy
import raced the render and encoded each pool buffer's PREVIOUS
contents. Fix, in order of preference:
- Consumer-side PipeWire explicit sync (SPA_META_SyncTimeline): new
drm_sync module (DRM timeline-syncobj wait/signal via raw ioctls,
unit-tested incl. a live signal->wait round trip); announced
post-format via update_params (the OBS pattern — at connect time
the meta makes producers fail allocation, observed on KWin), with
a blocks=3 Buffers filter so the producer's sync pod wins; acquire
point awaited before any read (GPU import or CPU mmap), release
point signaled on every path.
- Where the producer can't do explicit sync (Mutter on NVIDIA today:
no cogl sync_fd, "error alloc buffers"), a sticky fallback flips
the capture to the synchronous CPU/shm path — Mutter's glReadPixels
download orders against its render, so frames are correct by
construction. First session pays one ~10 s probe+retry; later
sessions go straight there. Validated live on home-worker-3
(GNOME 50 + RTX 4090): clean fallback, 30 MB HEVC streamed.
- Sync is only announced on Mutter sessions (new VirtualOutput.mutter
tag): KWin+NVIDIA fails allocation when merely asked, and doesn't
need it (verified unchanged: zero-copy CUDA import + 1.1 MB/10 s).
PUNKTFUNK_EXPLICIT_SYNC=0 disables the probe outright.
2. Clicks wedged in the focused app after disconnect+reconnect: a client
vanishing mid-press left keys/buttons latched in the compositor —
Mutter keeps the destroyed EIS device's implicit grab and the focused
app stops taking clicks until restarted. EiState now tracks held
keys/buttons/touches (wire codes) and synthesizes releases through
the normal inject path before the EIS connection goes away.
GNOME hosts on NVIDIA temporarily lose zero-copy (correctness over
throughput); the moment Mutter+driver gain working explicit sync, the
sync path engages automatically and zero-copy returns.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Hardens the virtual-display → capture → encode bring-up against the transient
failures that surfaced as black screens / wrong refresh on cold KDE sessions.
- m3: build_pipeline_with_retry wraps the initial vd.create() + first-frame with
bounded exponential backoff (4 attempts, 500ms→2s). is_permanent_build_error
classifies config/version/missing-tool failures so they fail fast instead of
burning the retry budget. Encoder + frame clock now pace to the *achieved*
refresh reported in VirtualOutput::preferred_mode, not the requested rate.
- capture/linux: PortalCapturer::Drop sends a pipewire channel quit and joins the
thread, so a dropped/failed/retried capturer releases its PipeWire thread + EGL/
CUDA context promptly instead of leaking it to process exit. First-frame timeout
now reports the node id and distinguishes "format never negotiated" from
"negotiated but no buffers arrived" via a negotiated flag set in param_changed.
- vdisplay/kwin: set_custom_refresh reads back the active mode from kscreen-doctor
and returns the refresh KWin actually gave us (a rejected custom mode silently
leaves the output at 60Hz); create() carries it into preferred_mode.
- vdisplay/gamescope: find_gamescope_node requires the Video/Source object (the
node.name=gamescope tag is on two objects; the other wedges the link); a version
check warns on <3.16.22 (the PipeWire-1.6 capture-deadlock signature).
Live-validated against headless KWin: 720p120 build with requested=120 achieved=120,
zero-copy CUDA frames, and no per-session thread accumulation across back-to-back
sessions. Tests: +3 unit (retry classifier, gamescope version parse); 49 host tests
green, clippy/fmt clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Full project rename, decided 2026-06-10:
- Crates/binaries: punktfunk-core / punktfunk-host / punktfunk-client-rs.
- C ABI: punktfunk_* symbols, Punktfunk* types, include/punktfunk_core.h,
PUNKTFUNK_FEATURE_QUIC guard (header regenerated; cbindgen renames updated, incl.
PUNKTFUNK_BTN_*/PUNKTFUNK_AXIS_* wire constants).
- Protocol: punktfunk/1 — control-plane magic LMN1 → PKF1, nonce salt lmn1 → pkf1.
WIRE BREAK: clients must be rebuilt from this revision.
- Env knobs: PUNKTFUNK_VIDEO_SOURCE / PUNKTFUNK_COMPOSITOR / PUNKTFUNK_ZEROCOPY / ….
- Host config dir: ~/.config/punktfunk (the box's dir was migrated in place — the
persistent identity is unchanged, pinned fingerprints stay valid).
- Swift package: PunktfunkKit + PunktfunkCore.xcframework + PunktfunkConnection
(Sources/PunktfunkClient app + tests renamed with it); build-xcframework.sh updated.
- scripts/: 60-punktfunk.rules, punktfunk-host.service; OpenAPI doc regenerated.
Also: scripts/headless/run-headless-kde.sh — full headless Plasma bringup. Root cause of
"desktop but no apps/settings" over the stream: plasmashell launched without
XDG_MENU_PREFIX=plasma-, so the launcher resolved a nonexistent applications.menu and
rendered an empty menu. The script sets the complete KDE session env (menu prefix,
KDE_FULL_SESSION, session version) and rebuilds ksycoca before starting plasmashell.
Gate: 97/97 tests, clippy -D warnings (both feature sets), fmt, C-ABI harness PASS,
zero lumen references left outside .git.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler