flightlessmango
Plasma desktop environment doesn't load (start) when Vulkan is forced directly or indirectly through environmet variables
Describe the bug Plasma desktop environment (made by KDE) doesn't load (start) when Vulkan is forced directly or indirectly through environment variables.
List relevant hardware/software information
- Linux Distribution: Debian 14 (AKA Forky | testing repository)
- Desktop environment: Plasma 6.5.3 (Wayland session)
- MangoHud version: v0.8.1 (latest in repository ATM)
- GPU: Intel UHD 620 (integrated) and AMD R5 (discrete)
To Reproduce Steps to reproduce the behavior:
- Add these environment variables somewhere where they are loaded globally: MANGOHUD=1 MANGOHUD_CONFIGFILE=/etc/MangoHud.conf QSG_RHI_BACKEND=vulkan
- Save and restart the computer
Expected behavior Plasma desktop environment should load (start, log in) normally.
Additional context If you managed to log in successfully or not, open the same file where you put the above environment variables and change this one: QSG_RHI_BACKEND=vulkan with: MESA_LOADER_DRIVER_OVERRIDE=zink Which should force OpenGL on Vulkan, instead of just Vulkan. And restart the computer! In my case Plasma didn't load at all initially and after a few updates, it now starts, but everything crashes a lot that is completely unusable. MangoHUD appears in some parts. KDE developers think that it's a bug in MangoHUD: https://bugs.kde.org/show_bug.cgi?id=501488 Can you please check if this is indeed a bug in MangoHUD? And if it's not, it's something that you can change in MangoHUD so Plasma doesn't break so much when Vulkan support is forced with: QSG_RHI_BACKEND=vulkan Or OpenGL on Vulkan is forced, through Zink is forced with: MESA_LOADER_DRIVER_OVERRIDE=zink ?
I would prefer to continue to enable MangoHUD globally so I don't have to enable it manually for every single game. But at the same time it would be nice if Plasma would continue to work normally when vulkan is forced directly or though Zink. If nothing can be done here, I would still be happy to hear if this is indeed a bug in MangoHUD or not.
BTW, I'm not sure if it's releated to this in any way or helpful at all, but when I run the 'vkcube' command I see MangoHUD mentioned in a warning:
Selected WSI platform: wayland
[2025-12-09 00:26:05.626] [MANGOHUD] [warning] [gpu_fdinfo.cpp:419] Intel i915 gt dir: failed to open /sys/bus/pci/devices/0000:00:02.0/drm/card0/gt/gt0/throttle_reason_status
Selected GPU 1: AMD Radeon R5 M465 Series (RADV ICELAND), type: DiscreteGpu
The 'warning' inside the brackets is colored in yellow.
Yeah this is why we don't recommend injecting mangohud into any and all applications. Best solution for right now would be to not set mangohud system wide but desktop wide
https://userbase.kde.org/Session_Environment_Variables
