Qdbus /usr/lib/qt6/bin/qdbus has encountered a fatal error and was closed

Help
1

Hello, don’t know what’s happening but since a few days I received this message:

/usr/lib/qt6/bin/qdbus has encountered a fatal error and was closed.

I don’t notice any issues during normal operation, but I get this message right after startup

           PID: 2646 (qdbus)
           UID: 1000 (swh)
           GID: 1000 (swh)
        Signal: 11 (SEGV)
     Timestamp: Mon 2026-03-30 09:38:11 CEST (1min 25s ago)
  Command Line: /usr/lib/qt6/bin/qdbus org.kde.kglobalaccel /component/kwin org.kde.kglobalaccel.Component.shortcutNames
    Executable: /usr/lib/qt6/bin/qdbus
 Control Group: /user.slice/user-1000.slice/user@1000.service/session.slice/plasma-plasmashell.service
          Unit: user@1000.service
     User Unit: plasma-plasmashell.service
         Slice: user-1000.slice
     Owner UID: 1000 (swh)
       Boot ID: 1dfedd4d8ef1401087021769fb078f0b
    Machine ID: 6001749eb9ce4cdeb3c1789e21e4c0eb
      Hostname: starship
       Storage: /var/lib/systemd/coredump/core.qdbus.1000.1dfedd4d8ef1401087021769fb078f0b.2646.1774856291000000.zst (present)
  Size on Disk: 196.4K
       Message: Process 2646 (qdbus) of user 1000 dumped core.
                
                Stack trace of thread 2646:
                #0  0x00007f442b2a74d1 n/a (libQt6Core.so.6 + 0xa74d1)
                #1  0x00007f442ba1a9eb n/a (libQt6DBus.so.6 + 0x5e9eb)
                #2  0x00007f442ac4fa61 n/a (libc.so.6 + 0x40a61)
                #3  0x00007f442ac4fb3e exit (libc.so.6 + 0x40b3e)
                #4  0x00007f442ac366c8 n/a (libc.so.6 + 0x276c8)
                #5  0x00007f442ac367f9 __libc_start_main (libc.so.6 + 0x277f9)
                #6  0x000055e640430745 n/a (/usr/lib/qt6/bin/qdbus + 0x6745)
                
                Stack trace of thread 2651:
                #0  0x00007f442acadf32 n/a (libc.so.6 + 0x9ef32)
                #1  0x00007f442aca239c n/a (libc.so.6 + 0x9339c)
                #2  0x00007f442aca23e4 n/a (libc.so.6 + 0x933e4)
                #3  0x00007f442ad1c2f6 ppoll (libc.so.6 + 0x10d2f6)
                #4  0x00007f442b108744 n/a (libglib-2.0.so.0 + 0x60744)
                #5  0x00007f442b108825 g_main_context_iteration (libglib-2.0.so.0 + 0x60825)
                #6  0x00007f442b672222 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x472222)
                #7  0x00007f442b3845d6 _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x1845d6)
                #8  0x00007f442b49efa2 _ZN7QThread4execEv (libQt6Core.so.6 + 0x29efa2)
                #9  0x00007f442b9f350e n/a (libQt6DBus.so.6 + 0x3750e)
                #10 0x00007f442b54d483 n/a (libQt6Core.so.6 + 0x34d483)
                #11 0x00007f442aca597a n/a (libc.so.6 + 0x9697a)
                #12 0x00007f442ad292bc n/a (libc.so.6 + 0x11a2bc)
                ELF object binary architecture: AMD x86-64

Any help is highly appreciate

2

I have roughtly the same issue at every Plasma startup since a few days :

image
image428×285 27.6 KB

I am on KDE Linux, I am curious to know on what distro you are.

3

I am on EndeavourOS

4

Okay

My guess right now (I might wrong) is that problem is caused by upstream Qt 6.11 that has been released a week ago.

It might be fixed upstream idk.

1 Like
5

Very likely. qdbus is a Qt tool; not something to do with KDE.

1 Like
6

There are widgets that use qdbus like GitHub - antroids/application-title-bar: KDE Plasma6 widget with window controls · GitHub this is why the error is shown on boot or interacting with these widgets application-title-bar/issues/91

The problem has been reported to Qt: qdbus CLI segfaults on 6.11.0

One can see which widgets/wallpapers/scripts are calling qdbus with ripgrep:

rg -ig "*.{qml,sh,js,xml}" 'qdbus' $HOME/.local/share/{kwin,plasma} /usr/share/{kwin,plasma}

It can also be some script

3 Likes
7

@ngraham Thanks for reply

@luisbocanegra I think I understand it. actually I have ApplicationTitleBar and your klassy with class .* as window specific override

Thank you for your kind explanation

╰─❯  rg -ig "*.{qml,sh,js,xml}" 'qdbus' $HOME/.local/share/{kwin,plasma} /usr/share/{kwin,plasma}
rg: /home/swh/.local/share/kwin: No such file or directory (os error 2)
/home/swh/.local/share/plasma/look-and-feel/swhgitpurple/contents/layouts/org.kde.plasma.desktop-layout.js
388:                            "knownApps": "org.kde.accessibilityinspector.desktop,org.kde.kaddressbook.desktop,org.kde.akonadiconsole.desktop,org.kde.akregator.desktop,org.kde.alligator.desktop,org.kde.amarok.desktop,org.kde.angelfish.desktop,org.kde.arianna.desktop,org.kde.ark.desktop,org.kde.artikulate.desktop,asunder.desktop,audacious.desktop,org.kde.audex.desktop,org.kde.audiotube.desktop,bssh.desktop,bvnc.desktop,avahi-discover.desktop,org.kde.plasma-welcome.desktop,org.kde.drkonqi.coredump.gui.desktop,blender.desktop,org.kde.blinken.desktop,org.kde.bomber.desktop,org.kde.bovo.desktop,brave-browser.desktop,btop.desktop,calibre-gui.desktop,org.kde.calligra.desktop,org.kde.calligra.sheets.desktop,org.kde.calligra.stage.desktop,org.kde.calligra.words.desktop,dog.unix.cantata.Cantata.desktop,org.kde.cantor.desktop,cmake-gui.desktop,io.github.nate_xyz.Conjure.desktop,net.fasterland.converseen.desktop,org.corectrl.CoreCtrl.desktop,deadbeef.desktop,org.kde.contactthemeeditor.desktop,Dicomizer.desktop,org.kde.dolphin.desktop,org.kde.dragonplayer.desktop,org.kde.contactprintthemeeditor.desktop,calibre-ebook-edit.desktop,calibre-ebook-viewer.desktop,com.github.wwmm.easyeffects.desktop,easytag.desktop,org.kde.elisa.desktop,org.kde.plasma.emojier.desktop,eos-apps-info.desktop,eos-log-tool.desktop,eos-quickstart.desktop,eos-update.desktop,org.kde.falkon.desktop,org.kde.filelight.desktop,filezilla.desktop,firefox.desktop,firewall-config.desktop,org.fooyin.fooyin.desktop,org.kde.koko.desktop,org.kde.francis.desktop,Fred TV.desktop,Freetube.desktop,furmark.desktop,gmic_qt.desktop,gaiasky.desktop,com.mitchellh.ghostty.desktop,org.kde.ghostwriter.desktop,org.kde.plasma.lookandfeelexplorer.desktop,gimp.desktop,org.kde.kwatchgnupg.desktop,org.kde.granatier.desktop,grsync.desktop,org.kde.gwenview.desktop,fr.handbrake.ghb.desktop,hardinfo2.desktop,lstopo.desktop,org.kde.haruna.desktop,org.kde.khelpcenter.desktop,htop.desktop,yad-icon-browser.desktop,org.kde.iconexplorer.desktop,org.kde.kinfocenter.desktop,org.inkscape.Inkscape.desktop,org.kde.isoimagewriter.desktop,org.kde.kjournaldbrowser.desktop,org.kde.juk.desktop,org.kde.k3b.desktop,org.kde.kajongg.desktop,org.kde.kalarm.desktop,org.kde.kalgebra.desktop,org.kde.kalgebramobile.desktop,org.kde.kalm.desktop,org.kde.kalzium.desktop,org.kde.kamoso.desktop,org.kde.kanagram.desktop,org.kde.kapman.desktop,org.kde.kapptemplate.desktop,org.kde.calligra.karbon.desktop,org.kde.ktuberling.desktop,org.kde.kasts.desktop,org.kde.kate.desktop,org.kde.katomic.desktop,org.kde.kbackup.desktop,org.kde.kblackbox.desktop,org.kde.kblocks.desktop,org.kde.kbounce.desktop,org.kde.kbreakout.desktop,org.kde.kbruch.desktop,org.kde.kcachegrind.desktop,org.kde.kcalc.desktop,org.kde.kcharselect.desktop,org.kde.kcolorchooser.desktop,org.kde.kdeconnect.app.desktop,org.kde.kdeconnect.sms.desktop,org.kde.itinerary.desktop,org.kde.kosmindoormap.desktop,org.kde.marble.desktop,org.kde.partitionmanager.desktop,org.kde.kdebugsettings.desktop,org.kde.kdenlive.desktop,org.kde.kdevelop.desktop,org.kde.kdevelop_ps.desktop,org.kde.kdiamond.desktop,org.kde.kdf.desktop,org.keepassxc.KeePassXC.desktop,org.kde.keysmith.desktop,org.kde.kfind.desktop,org.kde.kgeography.desktop,org.kde.kget.desktop,org.kde.kgoldrunner.desktop,org.kde.kgpg.desktop,org.kde.kgraphviewer.desktop,org.kde.khangman.desktop,org.kde.kid3.desktop,org.kde.kig.desktop,org.kde.kigo.desktop,org.kde.killbots.desktop,org.kde.kimagemapeditor.desktop,org.kde.kirigami2.gallery.desktop,org.kde.kiriki.desktop,org.kde.kiten.desktop,kitty.desktop,org.kde.kjumpingcube.desktop,klassy-settings.desktop,org.kde.kleopatra.desktop,org.kde.klettres.desktop,org.kde.klickety.desktop,org.kde.kmag.desktop,org.kde.kmahjongg.desktop,org.kde.kmail2.desktop,org.kde.headerthemeeditor.desktop,org.kde.akonadiimportwizard.desktop,org.kde.kmines.desktop,org.kde.kmix.desktop,org.kde.kmousetool.desktop,org.kde.kmouth.desktop,org.kde.kmplot.desktop,org.kde.knetwalk.desktop,org.kde.knights.desktop,org.kde.kolf.desktop,org.kde.kollision.desktop,org.kde.klines.desktop,org.kde.kolourpaint.desktop,org.kde.kompare.desktop,org.kde.kongress.desktop,konqbrowser.desktop,org.kde.konquest.desktop,org.kde.konsole.desktop,org.kde.kontact.desktop,org.kde.kontrast.desktop,org.kde.konversation.desktop,org.kde.korganizer.desktop,org.kde.kpat.desktop,org.kde.krdc.desktop,org.kde.kreversi.desktop,org.kde.krfb.desktop,org.kde.kruler.desktop,org.kde.krusader.desktop,org.kde.ksirk.desktop,org.kde.ksirkskineditor.desktop,org.kde.ksnakeduel.desktop,org.kde.kspaceduel.desktop,org.kde.ksquares.desktop,org.kde.ksudoku.desktop,org.kde.ksystemlog.desktop,org.kde.kteatime.desktop,org.kde.ktimer.desktop,org.kde.ktnef.desktop,org.kde.ktorrent.desktop,org.kde.ktouch.desktop,org.kde.ktrip.desktop,org.kde.kturtle.desktop,org.kde.kubrick.desktop,org.kde.kuiviewer.desktop,kvantummanager.desktop,org.kde.kwalletmanager.desktop,org.kde.kwave.desktop,org.kde.kwikdisk.desktop,org.kde.kwrite.desktop,org.kde.labplot.desktop,org.pulseaudio.pavucontrol.desktop,libreoffice-startcenter.desktop,libreoffice-base.desktop,libreoffice-calc.desktop,libreoffice-draw.desktop,libreoffice-impress.desktop,libreoffice-math.desktop,libreoffice-writer.desktop,librewolf.desktop,localsend.desktop,org.kde.lokalize.desktop,losslesscut-bin.desktop,calibre-lrfviewer.desktop,org.kde.lskat.desktop,makemkv.desktop,org.kde.massif-visualizer.desktop,mediainfo-gui.desktop,org.gnome.Meld.desktop,org.kde.kmenuedit.desktop,org.kde.merkuro.calendar.desktop,org.kde.merkuro.contact.desktop,fr.romainvigier.MetadataCleaner.desktop,org.kde.minuet.desktop,io.missioncenter.MissionCenter.desktop,mpv.desktop,mtplayer.desktop,mullvad-browser.desktop,org.kde.knavalbattle.desktop,org.kde.neochat.desktop,nvtop.desktop,nyxt.desktop,org.kde.okular.desktop,jconsole-java-openjdk.desktop,jshell-java-openjdk.desktop,org.moson.pacseek.desktop,org.kde.palapeli.desktop,org.kde.parley.desktop,org.kde.picmi.desktop,org.kde.pimdataexporter.desktop,org.kde.plasmaengineexplorer.desktop,org.kde.plasma.themeexplorer.desktop,org.kde.plasmatube.desktop,org.qbittorrent.qBittorrent.desktop,assistant.desktop,qdbusviewer.desktop,linguist.desktop,qv4l2.desktop,qvidcap.desktop,designer.desktop,org.kde.kalk.desktop,org.kde.krecorder.desktop,reflector-simple.desktop,org.kde.rocs.desktop,org.kde.ksame.desktop,scrcpy.desktop,scrcpy-console.desktop,kde-material-you-colors-screenshot-helper.desktop,org.kde.kshisen.desktop,org.shotcut.Shotcut.desktop,org.kde.sieveeditor.desktop,org.kde.skanlite.desktop,org.kde.skanpage.desktop,org.kde.skladnik.desktop,org.kde.skrooge.desktop,stoken-gui.desktop,stoken-gui-small.desktop,org.kde.spectacle.desktop,org.stellarium.Stellarium.desktop,org.kde.step.desktop,org.strawberrymusicplayer.strawberry.desktop,supertuxkart.desktop,org.kde.sweeper.desktop,sweethome3d.desktop,systemsettings.desktop,org.kde.plasma-systemmonitor.desktop,tauonmb.desktop,org.telegram.desktop.desktop,org.kde.telly-skout.desktop,org.kde.tokodon.desktop,tutanota-desktop.desktop,org.kde.kclock.desktop,org.kde.umbrello.desktop,uxterm.desktop,org.kde.kfourinline.desktop,vim.desktop,vivaldi-stable.desktop,vlc.desktop,Weasis.desktop,org.kde.kweather.desktop,welcome.desktop,org.kde.kwordquiz.desktop,xgps.desktop,xgpsspeed.desktop,xterm.desktop,yad-settings.desktop,org.kde.yakuake.desktop,yazi.desktop,org.kde.zanshin.desktop",

/home/swh/.local/share/plasma/plasmoids/com.github.antroids.application-title-bar/contents/ui/KWinConfig.qml
17:    property string reconfigureCommand: qdbusCommandName !== "" ? qdbusCommandName + " org.kde.KWin /KWin reconfigure" : ""
18:    property string getAllKWinShortcutNamesCommand: qdbusCommandName !== "" ? qdbusCommandName + " org.kde.kglobalaccel /component/kwin org.kde.kglobalaccel.Component.shortcutNames" : ""
19:    property string invokeKWinShortcutCommand: qdbusCommandName !== "" ? qdbusCommandName + " org.kde.kglobalaccel /component/kwin org.kde.kglobalaccel.Component.invokeShortcut " : ""
25:    property string qdbusCommandName: "qdbus"
121:    function updateQdbusCommandName() {
122:        updateCommandName(["/usr/lib/qt6/bin/qdbus", "qdbus", "qdbus6", "qdbus-qt6"], function (commandName) {
123:            qdbusCommandName = commandName;
124:            qdbusCommandNameChanged();
210:        updateQdbusCommandName();
215:    onQdbusCommandNameChanged: function () {

/home/swh/.local/share/plasma/plasmoids/com.github.antroids.application-title-bar/contents/ui/config/ConfigBehavior.qml
69:            text: "QDbus command is missing in the system!"
71:            visible: kWinConfig.qdbusCommandName === ""

/usr/share/plasma/plasmoids/luisbocanegra.panel.colorizer/contents/ui/configGeneral.qml
279:                text: "qdbus6 " + dbusName + " /preset preset /path/to/preset/dir/"
287:                text: i18n("Preview and switch presets using fzf + qdbus6 + jq:")
291:                text: "find " + presetsBuiltinDir + " " + presetsDir + " -mindepth 1 -prune -type d | fzf --preview 'qdbus6 " + dbusName + " /preset preset {} && jq --color-output . {}/settings.json'"
303:                text: `qdbus6 ${root.dbusName} /preset property 'stockPanelSettings.visible {"enabled": true, "value": false}'`
311:                text: `qdbus6 ${root.dbusName} /preset property 'stockPanelSettings.visible {"enabled": true, "value": true}'
8

I didn’t create, or work on Klassy, but I maintain panel colorizer (it appears in your ripgrep).

My widgets are not affected by this bug because I moved them to gdbus, mainly to avoid doing the lookup of the qdbus binary that has different names depending on distribution but also to support data types that qdbus can’t handle. The lines you see are just example commands for the user.

1 Like
9

Yes I Know. Sorry I mistyped it. It’s @paulm who work on klassy.

I just wanted to make it clear that I’m using klassy with this configuration. Without window decoration but with ApplicationTitleBar.

I understood that.
But I don’t have the knowledge to understand how the widgets work with dbus and how everything is connected.

I’m just a simple user who always has some questions

10

Cool, that’s basically my setup.

It’s good to question how things work, I started like that and now have like ten add-ons because I love messing with stuff haha. Basically widgets can use D-Bus through the qdbus program to get information or functionality that is provided by other programs running in the system

While there are other ways to interact with D-Bus, using qdbus is common for scripts and widgets because it is easier to run a shell command than using native C++ plugins as the later would prevent easy installation through the KDE store

1 Like
11

I updated this week. Error message seems to have disappeared. Everything is fine again