Global menu on Wayland

[sfjuocekr]

kded6 (6.5.0) throws the not very descriptive error:

org.kde.plasma.appmenu: Got an error

It does this four times successively and fails to populate the global menu.

This is on Arch with Plasma on Wayland, it works fine on X11.

[sfjuocekr]

Might actually be a kded6 issue!

When kded6 is started on a Wayland session with QT_QPA_PLATFORM=wayland the appmenu does not work for some "non-QT" applications, when it is started with QT_QPA_PLATFORM=xcb it does work but then things like scaling do not apply correctly.

I raised a bug with KDE as well, I will have to update my findings there as well as I think this belongs there.

[sfjuocekr]

@falkTX I noticed you added QT6 support in the recent commits, how do I force the QT6 frontend?

I see in the code the check for 5 happens before 6 on quite a few occasions, this likely uses QT5 whenever it is available instead of QT6?

[nikAizuddin]

how do I force the QT6 frontend?

You can force Qt6 by setting FRONTEND_TYPE = 6 at this line

Carla/source/Makefile.deps.mk

Line 364 in 2f7c939

FRONTEND_TYPE = 5

Carla does detect Qt6 and compilation works:

$ make features PKG_CONFIG_PATH="${HOME}/.local/opt/qt6/lib/pkgconfig:${HOME}/.vcpkg-clion/carla/installed/x64-linux-dynamic/lib/pkgconfig"

---> Main features 
Front-End:     YES (Qt6)
LV2 plugin:    YES
VST2 plugin:   YES
Link support:  YES
OSC support:   YES
Binary detect: YES

---> Engine drivers 
JACK:        YES
ALSA:        YES
PulseAudio:  YES
CoreAudio:   NO  [MacOS only]
DirectSound: NO  [Windows only]
WASAPI:      NO  [Windows only]
SDL:         YES

---> Plugin formats: 
Internal: YES
LADSPA:   YES
DSSI:     YES
LV2:      YES
CLAP:     YES
VST2:     YES (with UI)
VST3:     YES (with UI)
AU:       NO  [MacOS only]

---> LV2 UI toolkit support: 
External: YES (direct)
Gtk2:     YES (bridge)
Gtk3:     YES (bridge)
Qt4:      NO  [Qt4 missing]
Qt5:      YES (bridge)
X11:      YES (direct+bridge)
Cocoa:    NO  [MacOS only]
Windows:  NO  [Windows only]

---> File formats: 
Basic: YES
MP3:   YES
Extra: NO [FFmpeg missing or too new]
SF2/3: NO [FluidSynth missing or too old]
SFZ:   YES

---> Internal plugins: 
Basic Plugins:    YES
Carla-Patchbay:   YES
Carla-Rack:       YES
External Plugins: NO

However, plugins that requires Qt5 (such as LSP Plugins) will not have GUI. My bad, I forgot to enable UI feature in LSP Plugins. So far I have no issues with this Qt6 forced build.

[falkTX]

you can force any makefile variable on the command-line, so this is enough:

make FRONTEND_TYPE=6

let me know if you find any issues related to Qt6 usage