OS: Kubuntu 19.04 xdg-desktop-portal-kde: 5.15.4 When I start a flatpak app that uses the KDE runtime, it takes quite a while until the window shows up. The same doesn't happen with Freedesktop or GNOME runtime based apps. Under journalctl I see the following errors: Apr 19 06:59:06 localhost polkitd(authority=local)[825]: Registered Authentication Agent for unix-process:4837:314908 (system bus name :1.312 [flatpak run org.shotcut.Shotcut], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale de_DE.UTF-8) Apr 19 06:59:06 localhost systemd[1162]: Started flatpak-org.shotcut.Shotcut-4837.scope. Apr 19 06:59:06 localhost polkitd(authority=local)[825]: Unregistered Authentication Agent for unix-process:4837:314908 (system bus name :1.312, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale de_DE.UTF-8) (disconnected from bus) Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: ReadAll called with parameters: Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: groups: ("org.kde.kdeglobals.*") Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Read called with parameters: Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: group: "org.kde.kdeglobals.General" Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: key: "menuFont" Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Key "menuFont" doesn't exist Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusMarshaller: cannot add a null QDBusVariant Apr 19 06:59:06 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusConnection: error: could not send reply message to service "": Marshalling failed: Variant containing QVariant::Invalid passed in arguments Apr 19 06:59:31 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Read called with parameters: Apr 19 06:59:31 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: group: "org.kde.kdeglobals.General" Apr 19 06:59:31 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: key: "font" Apr 19 06:59:31 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Key "font" doesn't exist Apr 19 06:59:31 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusMarshaller: cannot add a null QDBusVariant Apr 19 06:59:31 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusConnection: error: could not send reply message to service "": Marshalling failed: Variant containing QVariant::Invalid passed in arguments Apr 19 06:59:56 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Read called with parameters: Apr 19 06:59:56 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: group: "org.kde.kdeglobals.WM" Apr 19 06:59:56 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: key: "activeFont" Apr 19 06:59:56 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Key "activeFont" doesn't exist Apr 19 06:59:56 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusMarshaller: cannot add a null QDBusVariant Apr 19 06:59:56 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusConnection: error: could not send reply message to service "": Marshalling failed: Variant containing QVariant::Invalid passed in arguments Apr 19 07:00:21 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Read called with parameters: Apr 19 07:00:21 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: group: "org.kde.kdeglobals.General" Apr 19 07:00:21 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: key: "toolBarFont" Apr 19 07:00:21 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Key "toolBarFont" doesn't exist Apr 19 07:00:21 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusMarshaller: cannot add a null QDBusVariant Apr 19 07:00:21 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusConnection: error: could not send reply message to service "": Marshalling failed: Variant containing QVariant::Invalid passed in arguments Apr 19 07:00:46 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Read called with parameters: Apr 19 07:00:46 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: group: "org.kde.kdeglobals.General" Apr 19 07:00:46 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: key: "smallestReadableFont" Apr 19 07:00:46 localhost org.freedesktop.impl.portal.desktop.kde[1217]: xdp-kde-settings: Key "smallestReadableFont" doesn't exist Apr 19 07:00:46 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusMarshaller: cannot add a null QDBusVariant Apr 19 07:00:46 localhost org.freedesktop.impl.portal.desktop.kde[1217]: QDBusConnection: error: could not send reply message to service "": Marshalling failed: Variant containing QVariant::Invalid passed in arguments
I tested this with an app (io.github.cloose.CuteMarkEd) that is using KDE runtime 5.9 and with this app, there is NO delay!
Now I tested this under GNOME with xdg-desktop-portal-gtk and there I have no delay at all, also with the 5.12 runtime. So the problematic combination is: xdg-desktop-portal-kde + KDE runtime 5.12
Git commit 045302b5292cb62da5843906825c04898d6656d7 by Jan Grulich. Committed on 21/04/2019 at 18:52. Pushed by grulich into branch 'Plasma/5.15'. Settings portal: do not return QDBusVariant directly when calling Read() method It seems it's not possible to return an empty QDBusVariant, which makes our portal not to respond in time and delay application start. Instead of trying to return an empty QDBusVariant, we are supposed to return a DBus error. M +54 -20 src/settings.cpp M +4 -2 src/settings.h https://commits.kde.org/xdg-desktop-portal-kde/045302b5292cb62da5843906825c04898d6656d7
*** Bug 407572 has been marked as a duplicate of this bug. ***