SUMMARY Setting a Kirigami program to use the Material style from a qtquickcontrols2.conf file results in a segmentation fault, likely related to a cyclic dependency on Kirigami's Units.qml. STEPS TO REPRODUCE 1. Use KDE Frameworks 5.83.0 2. Create a basic Kirigami app; the template from KAppTemplate does the job. 3. Create a file named "qtquickcontrols2.conf" under "./src ". 4. Add the following contents to qtquickcontrols2.conf: [Controls] Style=Material 5. Load the file on the app as a resource, like so: <RCC> <qresource prefix="/"> <file alias="main.qml">contents/ui/main.qml</file> <file>qtquickcontrols2.conf</file> </qresource> </RCC> OBSERVED RESULT When the Control's style is set to Material, Kirigami app execution results in a segmentation fault as follows: Cyclic dependency detected between "file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/kirigami.2/Units.qml" and "file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/kirigami.2/Units.qml" *** Program received signal SIGSEGV (Segmentation fault) *** If you set the style to any other valid value, the program will run. If you replicate using a non-Kirigami template as your base, the program will run with any valid Style. EXPECTED RESULT One would expect Kirigami app to start with the Material theme, as they did in 5.82 and prior versions of KF5. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE neon 5.22 User Edition KDE Plasma Version: 5.22 KDE Frameworks Version: 5.83 Qt Version: 5.15.3 ADDITIONAL INFORMATION Graphics Platform: X11 Kernel Version: 5.8.0-55-lowlatency (64-bit)
#0 0x00007ffff6311435 in QQmlNotifier::emitNotify (endpoint=0x555555ba09c0, a=a@entry=0x7fffff7ffa60) at qml/qqmlnotifier.cpp:81 #1 0x00007ffff62b3fcf in QQmlData::signalEmitted (object=0x555555ba01a0, index=4, a=0x7fffff7ffa60) at qml/qqmlengine.cpp:834 #2 0x00007ffff6a42e75 in doActivate<false> (sender=0x555555ba01a0, signal_index=4, argv=0x7fffff7ffa60) at kernel/qobject_p.h:110 #3 0x00007ffff6a3c6b7 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7fffe8311700 <Kirigami::BasicThemeDefinition::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x7fffff7ffa60) at kernel/qobject.cpp:3946 #4 0x00007fffe82f60e6 in Kirigami::BasicThemeDefinition::sync (this=<optimized out>, _t1=<optimized out>) at src/libkirigami/KF5Kirigami2_autogen/EWIEGA46WW/moc_basictheme_p.cpp:751 #5 0x00007fffe830484f in Kirigami::BasicTheme::event (this=0x555555d3d490, event=0x7fffff7ffd40) at /usr/include/c++/9/bits/unique_ptr.h:374 #6 0x00007ffff74e4dc3 in QApplicationPrivate::notify_helper (this=this@entry=0x555555574a30, receiver=receiver@entry=0x555555d3d490, e=e@entry=0x7fffff7ffd40) at kernel/qapplication.cpp:3632 #7 0x00007ffff74edbb8 in QApplication::notify (this=0x7fffffffd990, receiver=0x555555d3d490, e=0x7fffff7ffd40) at kernel/qapplication.cpp:3156 #8 0x00007ffff6a0c2ca in QCoreApplication::notifyInternal2 (receiver=0x555555d3d490, event=0x7fffff7ffd40) at ../../include/QtCore/5.15.3/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:325 #9 0x00007fffe82f9cd4 in Kirigami::PlatformThemeData::notifyWatchers<QColor> (newValue=..., oldValue=..., sender=0x555555d3d490, this=0x555555d3d750) at /usr/include/x86_64-linux-gnu/qt5/QtGui/qcolor.h:92 #10 Kirigami::PlatformThemeData::setColor (color=..., role=Kirigami::PlatformThemeData::TextColor, sender=0x555555d3d490, this=0x555555d3d750) at /home/david/kde/src/kirigami/src/libkirigami/platformtheme.cpp:157 #11 Kirigami::PlatformThemePrivate::setDataColor (value=..., color=Kirigami::PlatformThemeData::TextColor, theme=0x555555d3d490, this=<optimized out>) at /home/david/kde/src/kirigami/src/libkirigami/platformtheme.cpp:341 #12 Kirigami::PlatformTheme::setTextColor (this=this@entry=0x555555d3d490, color=...) at /home/david/kde/src/kirigami/src/libkirigami/platformtheme.cpp:577 #13 0x00007fffe830454a in Kirigami::BasicTheme::sync (this=0x555555d3d490) at /home/david/kde/src/kirigami/src/libkirigami/basictheme.cpp:243 #14 0x00007fffe83012c4 in Kirigami::PlatformTheme::qmlAttachedProperties (object=0x5555556b0c80) at /home/david/kde/src/kirigami/src/libkirigami/platformtheme.cpp:880 #15 0x00007ffff62b52e3 in QtQml::resolveAttachedProperties (pf=<optimized out>, data=0x5555556b0d50, object=object@entry=0x5555556b0c80, create=create@entry=true) at qml/qqmlengine.cpp:1617 #16 0x00007ffff62b561e in QtQml::qmlAttachedPropertiesObject (object=object@entry=0x5555556b0c80, func=<optimized out>, create=create@entry=true) at qml/qqmlengine.cpp:1682 #17 0x00007ffff6348adb in QV4::QQmlTypeWrapper::virtualGet (m=0x7fffe8607470, id=..., receiver=0x7fffe8607470, hasProperty=0x0) at ../../include/QtQml/5.15.3/QtQml/private/../../../../../src/qml/qml/qqmlengine.h:172 #18 0x00007ffff615c67c in QV4::Object::get (receiver=0x7fffe8607470, hasProperty=0x0, name=0x7fffe8607478, this=0x7fffe8607470) at ../../include/QtQml/5.15.3/QtQml/private/../../../../../src/qml/jsruntime/qv4string_p.h:167 #19 QV4::Lookup::getterFallback (l=<optimized out>, engine=0x555555710bc0, object=...) at jsruntime/qv4lookup.cpp:201 #20 0x00007fffe3a540c0 in ?? () #21 0x0000000000000000 in ?? () Also happens with QT_QUICK_CONTROLS_STYLE="material"
A possibly relevant merge request was started @ https://invent.kde.org/frameworks/kirigami/-/merge_requests/319
Git commit 6f0833d55982d4502c8dba028f77d0596d8ed200 by David Redondo. Committed on 16/06/2021 at 13:10. Pushed by davidre into branch 'master'. Only emit sync signal if we have finished construction We cannot control what happens in slots connected to sync(). In particular our own Material style accesses the Theme attached property in onSync. If we have not finished construction the engine did not set the instance as the attachedObject and constructs a new one. This eventually triggers syncToQml() again and so on, causing a stack overflow. M +1 -1 src/libkirigami/basictheme.cpp https://invent.kde.org/frameworks/kirigami/commit/6f0833d55982d4502c8dba028f77d0596d8ed200