Segmentation fault (signal 11) on AMD integrated GPU (amdgpu 1002:1636) with Qt 6.11.0 + threaded render loop

[0xYurii]

What caused the crash

Environment:

• OS: Arch Linux (rolling)
• GPU: AMD Radeon integrated (amdgpu driver 3.64.0, model 1002:1636, PCI 06:00.0)
• Qt version: 6.11.0 (runtime and buildtime)
• Quickshell: 0.2.1 (revision 7c5a6c4, AUR package: quickshell-git)
• Config: caelestia shell (/etc/xdg/quickshell/caelestia/shell.qml)
• Render loop: QSG_RENDER_LOOP=threaded (set in environment)

What happened:
Quickshell crashes with a segmentation fault (signal 11) consistently after running for ~30-60 seconds. The crash occurs inside QCoreApplicationPrivate::sendPostedEvents → libc.

The last log entries before the crash show the shell loading bongocat.gif and shader assets (fade.frag.qsb), followed by a battery UPower property update, then immediate crash.

Crash location (stacktrace summary):
#0 libc.so.6
#1 QCoreApplicationPrivate::sendPostedEvents() - libQt6Core.so.6
#2 libQt6Core.so.6
#3-5 libglib-2.0.so.0 (g_main_context_iteration)
#6 QEventDispatcherGlib::processEvents() - libQt6Core.so.6
#7 QEventLoop::exec()
#8 QCoreApplication::exec()
#9 qs::launch::launch() - launch.cpp:267

text

Can you reproduce it?
Yes, happens on every session start within ~1 minute of the shell loading.

Workaround attempted:
Setting QSG_RENDER_LOOP=basic — currently testing.

Report file

report-2.txt

Log file

{redacted#62750386}

Configuration

using https://github.com/caelestia-dots/caelestia

Backtrace

No response

[outfoxxed]

You're the first person we've had who can reproduce this reliably.

I have a patch ready which should help us find this one but testing takes a couple steps.

1. Run quickshell with LD_PRELOAD=libqobject-hook.so (renamed to .txt for github upload) OR build the branch here: https://github.com/quickshell-mirror/quickshell/tree/notifyInternal2-crash-debug. Logs should be full of spam.
2. Get it to crash again and make sure the crash still has "sendPostedEvents" in it (it might be slightly different)
3. Send logs, report file, and the core file, which you can get using coredumpctl dump <pid> --output file.core. Also send the text coredumpctl dump prints in the terminal.

[ReillyBrogan]

Quickshell uses private Qt APIs and thus needs to be rebuilt on every Qt update. Has your Quickshell been rebuilt since your distribution updated to Qt 6.11.0?

Ah, just noticed you mention that it has been.