Bug 512193

Summary: Crashes While Changing Theme
Product: [Plasma] plasmashell Reporter: Tim <tda0626>
Component: generic-crashAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: crash CC: kdedev, q9hc26ia
Priority: NOR Keywords: drkonqi
Version First Reported In: 6.5.2   
Target Milestone: 1.0   
Platform: CachyOS   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report: https://crash-reports.kde.org/organizations/kde/issues/292487/events/36bbf02539784d99bd9ecbe2d71a17f0/
Attachments: New crash information added by DrKonqi

Description Tim 2025-11-16 15:06:16 UTC
Application: plasmashell (6.5.2)

ApplicationNotResponding [ANR]: false
Qt Version: 6.10.0
Frameworks Version: 6.19.0
Operating System: Linux 6.17.7-5-cachyos x86_64
Windowing System: Wayland
Distribution: CachyOS
DrKonqi: 6.5.2 [CoredumpBackend]

-- Information about the crash:
When changing the theme, the system will lockup and become unresponsive. Sometimes the wallpaper will not show and no matter what I choose it will just ignore it or the taskbar will be gone.  The themes used were default Breeze Dark, CachyOS Nord, and Breeze Twilight. Getting to a terminal and restarting sddm from there, it asks me to login like normal. After typing password, it will not load the desktop and it drops me back in to the login screen. Also, when changing themes, it wiped out my taskbar icons for the default.

The crash can be reproduced every time.

-- Backtrace (Reduced):
#6  0x00007f942d472975 in QQmlPrivate::loadFallbackAsVariant (lookup=0x563d9918ed60, object=0x563d9a375c90, target=0x7ffeb3f32388, aotContext=0x7ffeb3f324b0) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqml.cpp:1458
#7  QQmlPrivate::AOTCompiledContext::getObjectLookup (this=0x7ffeb3f324b0, index=<optimized out>, object=0x563d9a375c90, target=0x7ffeb3f32388) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqml.cpp:2813
#8  0x00007f941ff31979 in QmlCacheGeneratedCode::_qt_qml_plasma_applet_org_kde_plasma_kickoff_main_qml::aotBuiltFunctions::{lambda(QQmlPrivate::AOTCompiledContext const*, void**)#29}::operator()(QQmlPrivate::AOTCompiledContext const*, void**) const () at /usr/src/debug/plasma-desktop/build/applets/kickoff/.rcc/qmlcache/org.kde.plasma.kickoff_main_qml.cpp:7599
#9  QmlCacheGeneratedCode::_qt_qml_plasma_applet_org_kde_plasma_kickoff_main_qml::aotBuiltFunctions::{lambda(QQmlPrivate::AOTCompiledContext const*, void**)#29}::_FUN(QQmlPrivate::AOTCompiledContext const*, void**) () at /usr/src/debug/plasma-desktop/build/applets/kickoff/.rcc/qmlcache/org.kde.plasma.kickoff_main_qml.cpp:7623
#10 0x00007f942d43d894 in operator() (argc=<optimized out>, __closure=0x7ffeb3f32540, argv=0x7ffeb3f32850) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/jsruntime/qv4vme_moth.cpp:451
#11 QV4::coerceAndCall<(anonymous namespace)::AOTCompiledMetaMethod, QV4::Moth::VME::exec(QV4::MetaTypesStackFrame*, QV4::ExecutionEngine*)::<lambda(void**, int)> >(QV4::ExecutionEngine *, const (anonymous namespace)::AOTCompiledMetaMethod *, void **, const QMetaType *, int, struct {...}) (engine=engine@entry=0x563d985db210, typedFunction=typedFunction@entry=0x7ffeb3f32578, argv=<optimized out>, types=<optimized out>, argc=<optimized out>, call=...) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/jsruntime/qv4jscall_p.h:559
#12 0x00007f942d446cea in QV4::Moth::VME::exec (frame=0x7ffeb3f32660, engine=0x563d985db210) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/jsruntime/qv4stackframe_p.h:155
#13 0x00007f942d39741f in QV4::Moth::VME::exec (frame=0x7ffeb3f32660, engine=<optimized out>) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/jsruntime/qv4engine_p.h:824
#14 QV4::Function::call (this=0x563d98ec93d0, thisObject=0x563d9ac30d00, a=0x7ffeb3f32850, types=<optimized out>, argc=0, context=0x7f93812372b8) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/jsruntime/qv4function.cpp:36
#15 0x00007f942d4e81fa in QQmlJavaScriptExpression::evaluate (this=<optimized out>, a=<optimized out>, types=<optimized out>, argc=<optimized out>) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqmljavascriptexpression.cpp:270
#16 0x00007f942d4808ae in QQmlBinding::evaluate (this=0x563d9bfa7630, result=0x7ffeb3f32800, type=...) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqmlbinding_p.h:86
#17 QQmlBinding::doUpdate (this=0x563d9bfa7630, watcher=..., flags=..., scope=<optimized out>) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqmlbinding.cpp:702
#18 0x00007f942d4778d9 in QQmlBinding::update (this=0x563d9bfa7630, flags=...) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqmlbinding.cpp:165
#19 0x00007f942d51ffcd in QQmlObjectCreator::finalize (this=0x563d9a2deb80, interrupt=...) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqmlobjectcreator.cpp:1552
#20 0x00007f942d499fca in QQmlComponentPrivate::complete (enginePriv=0x563d9862ee30, state=state@entry=0x563d9952e4e0) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/ftw/qbipointer_p.h:133
#21 0x00007f942d49e462 in QQmlComponentPrivate::completeCreate (this=0x563d9952e460) at /usr/src/debug/qt6-declarative/qtdeclarative/src/qml/qml/qqmlcomponent.cpp:1344


Reported using DrKonqi
Comment 1 Tim 2025-11-16 15:06:18 UTC
Created attachment 186844 [details]
New crash information added by DrKonqi

DrKonqi auto-attaching complete backtrace.
Comment 2 GoldBarb 2025-11-18 17:01:19 UTC
Does this happen when changing global themes - when "Desktop and window layout" is checked
For example I can reproduce a plasmashell crash on both Archlinux and openSuse-TW.
Both are on QT6.10
Comment 3 Tim 2025-11-18 17:29:26 UTC
(In reply to GoldBarb from comment #2)
> Does this happen when changing global themes - when "Desktop and window
> layout" is checked
> For example I can reproduce a plasmashell crash on both Archlinux and
> openSuse-TW.
> Both are on QT6.10

Yes, it happens with those items checked and changing the theme. Also, it seems to randomly happen without theme changes. Sometimes, my Start Menu will not work and have to restart the Plasma Shell to fix it.
Comment 4 TraceyC 2025-11-19 18:57:11 UTC
Thank you for the bug report. Based on the backtrace this looks like a duplicate of bug 511923. 
See https://bugreports.qt.io/browse/QTBUG-139626

This should be fixed with Qt 6.10.1 in a few days

*** This bug has been marked as a duplicate of bug 511923 ***