Linux AppImage: WebKitWebProcess SIGABRT in createAudioSink — GST_PLUGIN_SYSTEM_PATH points at missing plugin dirs

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Summary

Berd 0.6.2's Linux AppImage aborts WebKitWebProcess (SIGABRT / SI_TKILL) a few seconds after first launch. The UI process stays up, so the window goes blank rather than the whole app disappearing.

This is the same packaging hole Buzz already diagnosed and fixed in block/buzz#2176. Berd did not get that shim.

Environment

• Berd 0.6.2 extracted AppImage (~/.local/opt/berd/squashfs-root)
• OS: Omarchy 4.0.0 (Arch Linux)
• Session: Hyprland / Wayland; GDK_BACKEND=x11 (linuxdeploy GTK hook)
• GPU: NVIDIA GeForce RTX 3060 Ti, driver 610.57.04
• Host GStreamer: 1.28.6 (gst-plugins-base installed)
• Bundled WebKitGTK 4.1 GNU build-id 2594e661ffa45aa2a47f83c2f2f10caaec9e273f

Not an OOM: ~9 GiB free, no oom-kill in the journal.

What happens

1. Launch Berd (gtk-launch Berd.desktop).
2. First-load renderer boots ([renderer] renderer booted (first load this install)).
3. ~8s later WebKitWebProcess calls abort(). systemd-coredump records it.
4. Main Berd process keeps running (ACP/npm install, goose serve). No replacement web process is spawned.

Reproduced twice on this machine (PIDs 116183 at 12:02 and 119514 at 12:11 NZST, 2026-08-25). Same abort offsets both times.

Abort site (from the core)

WTFCrashWithInfo in:

• file: Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp
• function: GstElement *WebCore::MediaPlayerPrivateGStreamer::createAudioSink()
• line: 1585

That is RELEASE_ASSERT(audioSink) after createPlatformAudioSink("video") returned NULL. The crashing thread still held the role string "video".

WebKit's binary also contains GStreamer element %s not found. Please install it.

Root cause

linuxdeploy's AppRun.wrapped force-sets:

GST_PLUGIN_SYSTEM_PATH=$APPDIR/usr/lib/gstreamer:$GST_PLUGIN_SYSTEM_PATH
GST_PLUGIN_SYSTEM_PATH_1_0=$APPDIR/usr/lib/gstreamer-1.0:$GST_PLUGIN_SYSTEM_PATH_1_0

A set GST_PLUGIN_SYSTEM_PATH_1_0 replaces GStreamer's compiled-in default search path. Those two directories do not exist in the Berd AppImage. Berd ships GStreamer libraries (libgstreamer-1.0.so.0, libgstaudio-1.0.so.0, …) but no plugin tree.

At the crash second, GStreamer wrote ~/.cache/gstreamer-1.0/registry.x86_64.bin — 76 bytes, version 1.23.90, zero plugins.

Berd's launcher (~/.local/bin/Berd) only sets WEBKIT_DMABUF_RENDERER_FORCE_SHM=1 on NVIDIA. It does not undo the GST override. There is no equivalent of Buzz's usr/bin/buzz-desktop GST shim.

This is not the NVIDIA DMA-BUF protocol crash. WEBKIT_DMABUF_RENDERER_FORCE_SHM=1 was already set.

Expected

Missing audio sink should fail the media element, not abort() the renderer. The AppImage should either ship GStreamer plugins or not replace the host plugin path (Buzz #2176).

Suggested fix

Port Buzz's desktop/scripts/fix-appimage.sh shim: after AppRun.wrapped rewrites GST_PLUGIN_*, drop values that point into $APPDIR so host GStreamer can resolve autoaudiosink / appsink / appsrc. Alternatively ship a real usr/lib/gstreamer-1.0 plugin set built against the bundled GStreamer.

Also worth a private GST_REGISTRY under ~/.local/share/xyz.block.berd/ so the AppImage does not clobber the desktop-wide registry (see block/buzz#2560).

Related

• Same abort, same WebKit build-id, on Buzz AppImage on this machine (filing separately).
• Not block/buzz#2338 (DMA-BUF).
• Not block/buzz#6339 (Ubuntu .deb + system webkit 2.52.3).

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Same abort on Buzz AppImage from this machine: block/buzz#6740