event loop: plugin UI is non-responding on linux.

[deeedob]

Hey, I'm facing issues when trying to load the plugin from a host. I'm pretty sure it's related to the automatic event loop attaching of Qt from a WId with QWindow::fromWinId(~). I've been struggling with this behavior of Qt for a longer time basically when we attach to a native XCB/Xlib platform window. So this problem is probably not originating from here per se but definitely be affected by it, at least on my machine. Has someone been observing similar problems on linux?

EndeavourOS Linux
6.2.11-zen1-1-zen
DE: kde-plasma
Qt6.5 static, namespaced build, as well the shared lib build without namespace

I'm facing these issues with both, the static local build and the remote build. It simply won't attach to the event loop and is therefore not loading the GUIs content. I've tested it with clap-host which logs:

(process:73848): GLib-CRITICAL **: 01:12:41.369: g_main_context_push_thread_default: assertion 'acquired_context' failed

aswell as bitwig, which states: Plug-in host is not responding

Please let me know if someone has faced this. I would love to further investigate the root cause and fix this problem. Is this working smoothly on e.g. Ubuntu?

[BeRo1985]

Not under Linux, also under Windows under my own DAW, which I'm developing currently. It hangs at clap_plugin_gui_t->create(plugin, 'win32', false) then forever, when I'm trying to open the GUI of these clap plugins here. But with the CLAP plugins from u-he it does work correctly with my own DAW.