https://bugs.kde.org/show_bug.cgi?id=466804
--- Comment #10 from Rafael <[email protected]> --- Still reproducible on Plasma 6.8.1 / qt6 6.12.0 (Arch, Wayland, RTX 5070 Ti) — but through the *setting*, not the code path that was fixed here. My ~/.config/kdeglobals contained: [QtQuickRendererSettings] SceneGraphBackend=software and KDEPlasmaPlatformTheme6 (PlasmaQtQuickSettings::RendererSettings, which calls QQuickWindow::setGraphicsApi()) applies it, forcing the software scene graph for every Qt Quick application. plasma-systemmonitor showed the "Fell back to software rendering because hardware acceleration is not available... Please check your graphics drivers." banner while the driver stack was healthy (eglinfo on the Wayland platform -> 4.6.0 NVIDIA 615.78.08; vulkaninfo lists the device). What pointed at this: QT_QPA_PLATFORMTHEME=qt6ct or gtk3 made the banner disappear, because those skip the code that reads the key. QT_QUICK_BACKEND=opengl and QT_QUICK_BACKEND=vulkan had no effect at all, which is the tell that the override happens in C++ after the environment is parsed. Two gaps that still look open on Plasma 6: 1. There is no UI for this setting any more (Plasma 5 had kcmshell5 qtquicksettings), yet the key is still honoured and survives config migration. A stale value is invisible and cannot be changed or cleared from the desktop. 2. The System Monitor banner blames the graphics driver when the user's own configuration asked for software rendering. Removing the section from kdeglobals fixed it: same launcher path (systemd-run --user --slice=app.slice /usr/bin/plasma-systemmonitor), Plasma platform theme still loaded, libEGL_nvidia now mapped and 105 nvidia mappings in /proc/<pid>/maps. No banner. -- You are receiving this mail because: You are watching all bug changes.
