Distro: Linux Mint 20.3 Cinnamon 64-bit
Flatpak version: 1.12.2.
Issue: I want Flatpak apps to use the same dark theme as my host system. I have Cinnamon set to use the “Mint-Y-Dark” theme. I installed the flatpak theme
org.gtk.Gtk3theme.Mint-Y-Dark from Flathub, and all GTK apps automatically use it, but apps using the KDE runtime don’t.
Following the advice of the Flatpak docs, I installed
org.kde.KStyle.Adwaita//5.15-21.08 from Flathub.
Far from fixing the problem, installing these runtimes results in all KDE apps being unable to launch!
flatpak run com.obsproject.Studio Gtk-Message: 15:53:26.231: Failed to load module "xapp-gtk3-module" (obs:2): GLib-GIO-ERROR **: 15:53:26.254: Settings schema 'org.cinnamon.desktop.interface' is not installed``` All other apps using the KDE runtime produce the same error. For example,
flatpak run org.kde.kolourpaint
Gtk-Message: 15:59:05.626: Failed to load module “xapp-gtk3-module”
(kolourpaint:2): GLib-GIO-ERROR **: 15:59:05.649: Settings schema ‘org.cinnamon.desktop.interface’ is not installed```
Uninstalling QGnomePlatform but leaving org.kde.KStyle.Adwaita allows KDE apps to launch, but they still don’t use my system’s dark theme. Installing QGnomePlatform but not KStyle.Adwaita gives the same issue as installing both.
org.cinnamon.desktop.interface does not seem to be a flatpak app or runtime, so I don’t know how to fix it.