In current git master, Discover is reproducibly hanging upon launch and then crashing. After I open Discover, it's responsive for a few moments, but then the UI freezes and it crashes. The backtrace is: Application: Discover (plasma-discover), signal: Segmentation fault Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Current thread is 1 (Thread 0x7fdb0fee5800 (LWP 27419))] Thread 12 (Thread 0x7fda9bfff700 (LWP 27438)): #0 0x00007fdb0b23fbf9 in __GI___poll (fds=0x7fdaa00057f0, nfds=1, timeout=19078) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x00007fdb0536d539 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0bb7a04b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #4 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007fdb0b949bba in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007fdb075096db in start_thread (arg=0x7fda9bfff700) at pthread_create.c:463 #8 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 11 (Thread 0x7fdab19be700 (LWP 27436)): #0 0x00007fdb0b23b0b4 in __GI___libc_read (fd=49, buf=0x7fdab19bdcd0, nbytes=16) at ../sysdeps/unix/sysv/linux/read.c:27 #1 0x00007fdb053b1cd0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d027 in g_main_context_check () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0536d4e0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007fdb0536d8d2 in g_main_loop_run () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007fdacdb7a026 in () at /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 #6 0x00007fdb05395105 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #7 0x00007fdb075096db in start_thread (arg=0x7fdab19be700) at pthread_create.c:463 #8 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 10 (Thread 0x7fdab3fff700 (LWP 27432)): #0 0x00007fdb0b23fbf9 in __GI___poll (fds=0x7fdaac0018a0, nfds=1, timeout=19078) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x00007fdb0536d539 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0bb7a04b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #4 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007fdb0b949bba in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007fdb075096db in start_thread (arg=0x7fdab3fff700) at pthread_create.c:463 #8 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 9 (Thread 0x7fdac2273700 (LWP 27431)): #0 0x00007fdb053b3049 in g_mutex_lock () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #1 0x00007fdb0536d638 in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d691 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb05395105 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007fdb075096db in start_thread (arg=0x7fdac2273700) at pthread_create.c:463 #5 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 8 (Thread 0x7fdaca6a8700 (LWP 27427)): #0 0x00007fdb0b23b0b4 in __GI___libc_read (fd=15, buf=0x7fdaca6a7b90, nbytes=16) at ../sysdeps/unix/sysv/linux/read.c:27 #1 0x00007fdb053b1cd0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d027 in g_main_context_check () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0536d4e0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007fdb0bb7a04b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007fdb0b949bba in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #8 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #9 0x00007fdb075096db in start_thread (arg=0x7fdaca6a8700) at pthread_create.c:463 #10 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 7 (Thread 0x7fdadf2df700 (LWP 27426)): #0 0x00007fdb0b23b0b4 in __GI___libc_read (fd=12, buf=0x7fdadf2deb20, nbytes=16) at ../sysdeps/unix/sysv/linux/read.c:27 #1 0x00007fdb053b1cd0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d027 in g_main_context_check () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0536d4e0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #5 0x00007fdb0bb7a04b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007fdb0b949bba in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #8 0x00007fdb0ea82826 in () at /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5 #9 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #10 0x00007fdb075096db in start_thread (arg=0x7fdadf2df700) at pthread_create.c:463 #11 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 6 (Thread 0x7fdae06fb700 (LWP 27425)): #0 0x00007fdb0750f9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55798fce475c) at ../sysdeps/unix/sysv/linux/futex-internal.h:88 #1 0x00007fdb0750f9f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55798fce4708, cond=0x55798fce4730) at pthread_cond_wait.c:502 #2 0x00007fdb0750f9f3 in __pthread_cond_wait (cond=0x55798fce4730, mutex=0x55798fce4708) at pthread_cond_wait.c:655 #3 0x00007fdae5fe0d5b in () at /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so #4 0x00007fdae5fe0bd7 in () at /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so #5 0x00007fdb075096db in start_thread (arg=0x7fdae06fb700) at pthread_create.c:463 #6 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 5 (Thread 0x7fdae0efc700 (LWP 27424)): #0 0x00007fdb0750f9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55798fce45f4) at ../sysdeps/unix/sysv/linux/futex-internal.h:88 #1 0x00007fdb0750f9f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x55798fce45a0, cond=0x55798fce45c8) at pthread_cond_wait.c:502 #2 0x00007fdb0750f9f3 in __pthread_cond_wait (cond=0x55798fce45c8, mutex=0x55798fce45a0) at pthread_cond_wait.c:655 #3 0x00007fdae5fe0d5b in () at /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so #4 0x00007fdae5fe0bd7 in () at /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so #5 0x00007fdb075096db in start_thread (arg=0x7fdae0efc700) at pthread_create.c:463 #6 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 4 (Thread 0x7fdaef5ef700 (LWP 27423)): #0 0x00007fdb053b3049 in g_mutex_lock () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #1 0x00007fdb0536cc81 in g_main_context_query () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d4b7 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #4 0x00007fdb0bb7a04b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007fdb0b949bba in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #7 0x00007fdb0c4ee4f5 in () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5 #8 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #9 0x00007fdb075096db in start_thread (arg=0x7fdaef5ef700) at pthread_create.c:463 #10 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 3 (Thread 0x7fdaf4b52700 (LWP 27422)): #0 0x00007fdb0b23fbf9 in __GI___poll (fds=0x7fdaf0018de0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x00007fdb0536d539 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #2 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #3 0x00007fdb0bb7a04b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #4 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007fdb0b949bba in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #6 0x00007fdb0d848e45 in () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5 #7 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #8 0x00007fdb075096db in start_thread (arg=0x7fdaf4b52700) at pthread_create.c:463 #9 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 2 (Thread 0x7fdafce2b700 (LWP 27421)): #0 0x00007fdb0b23fbf9 in __GI___poll (fds=0x7fdafce2aca8, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x00007fdb04aa1747 in () at /usr/lib/x86_64-linux-gnu/libxcb.so.1 #2 0x00007fdb04aa336a in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1 #3 0x00007fdaffdebed9 in () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #4 0x00007fdb0b954adb in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #5 0x00007fdb075096db in start_thread (arg=0x7fdafce2b700) at pthread_create.c:463 #6 0x00007fdb0b24c88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95 Thread 1 (Thread 0x7fdb0fee5800 (LWP 27419)): [KCrash Handler] #6 0x0000000000000000 in () #7 0x00007fdb0f58d613 in Category::blacklistPluginsInVector(QSet<QString> const&, QVector<Category*>&) () at /usr/lib/x86_64-linux-gnu/plasma-discover/libDiscoverCommon.so #8 0x00007fdb0f58d4ed in Category::blacklistPlugins(QSet<QString> const&) () at /usr/lib/x86_64-linux-gnu/plasma-discover/libDiscoverCommon.so #9 0x00007fdb0f58d65a in Category::blacklistPluginsInVector(QSet<QString> const&, QVector<Category*>&) () at /usr/lib/x86_64-linux-gnu/plasma-discover/libDiscoverCommon.so #10 0x00007fdb0f590cc1 in CategoryModel::blacklistPlugin(QString const&) () at /usr/lib/x86_64-linux-gnu/plasma-discover/libDiscoverCommon.so #11 0x00007fdb0f5a10fd in ResourcesModel::callerFetchingChanged() () at /usr/lib/x86_64-linux-gnu/plasma-discover/libDiscoverCommon.so #12 0x00007fdb0bb4f18f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #13 0x00007fdac80d9263 in KNSBackend::setFetching(bool) () at /usr/lib/x86_64-linux-gnu/qt5/plugins/discover/kns-backend.so #14 0x00007fdac80d940e in KNSBackend::markInvalid(QString const&) () at /usr/lib/x86_64-linux-gnu/qt5/plugins/discover/kns-backend.so #15 0x00007fdac80d9bdb in KNSBackend::signalErrorCode(KNSCore::ErrorCode const&, QString const&, QVariant const&) () at /usr/lib/x86_64-linux-gnu/qt5/plugins/discover/kns-backend.so #16 0x00007fdb0bb4f18f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #17 0x00007fdac35dfb1f in KNSCore::Engine::signalErrorCode(KNSCore::ErrorCode const&, QString const&, QVariant const&) () at /usr/lib/x86_64-linux-gnu/libKF5NewStuffCore.so.5 #18 0x00007fdac35a1ec2 in KNSCore::Engine::slotProvidersFailed() () at /usr/lib/x86_64-linux-gnu/libKF5NewStuffCore.so.5 #19 0x00007fdb0bb4f18f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #20 0x00007fdac35ca60d in KNSCore::XmlLoader::slotJobResult(KJob*) () at /usr/lib/x86_64-linux-gnu/libKF5NewStuffCore.so.5 #21 0x00007fdb0bb4f18f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #22 0x00007fdb0bfe4fdc in KJob::result(KJob*, KJob::QPrivateSignal) () at /usr/lib/x86_64-linux-gnu/libKF5CoreAddons.so.5 #23 0x00007fdb0bfe5b11 in KJob::finishJob(bool) () at /usr/lib/x86_64-linux-gnu/libKF5CoreAddons.so.5 #24 0x00007fdb0bb4f18f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #25 0x00007fdac35cd74c in () at /usr/lib/x86_64-linux-gnu/libKF5NewStuffCore.so.5 #26 0x00007fdb0bb4f18f in QMetaObject::activate(QObject*, int, int, void**) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #27 0x00007fdb09659dff in () at /usr/lib/x86_64-linux-gnu/libQt5Network.so.5 #28 0x00007fdb096ee299 in () at /usr/lib/x86_64-linux-gnu/libQt5Network.so.5 #29 0x00007fdb0bb4fbe2 in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #30 0x00007fdb0d138e1c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #31 0x00007fdb0d1403ef in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #32 0x00007fdb0bb1ffe8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #33 0x00007fdb0bb22b2d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #34 0x00007fdb0bb7a9f3 in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #35 0x00007fdb0536d387 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #36 0x00007fdb0536d5c0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #37 0x00007fdb0536d64c in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 #38 0x00007fdb0bb7a02f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #39 0x00007fdaffe77761 in () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5 #40 0x00007fdb0bb1e30a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #41 0x00007fdb0bb274d0 in QCoreApplication::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5 #42 0x000055798ef65bca in () #43 0x00007fdb0b14cb97 in __libc_start_main (main=0x55798ef65270, argc=1, argv=0x7ffe266a2c28, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe266a2c18) at ../csu/libc-start.c:310 #44 0x000055798ef65e5a in _start () Console spew is: $ plasma-discover adding empty sources model QStandardItemModel(0x5601d4281870) no packages for "org.kde.plasma.systemloadviewer" no packages for "org.kde.plasma.showActivityManager" no packages for "org.kde.plasma.grouping" no packages for "org.kde.discovernotifier" no packages for "org.kde.plasma.diskquota" no packages for "org.kde.kscreen" no packages for "org.kde.plasma.kimpanel" no packages for "org.kde.plasma.timer" no packages for "im.riot.webapp" no packages for "org.kde.plasma.appmenu" no packages for "org.kde.plasma.quicklaunch" invalid kns backend! "/etc/xdg/ksysguard.knsrc" because: "Config group not found! Check your KNS3 installation." invalid kns backend! "/etc/xdg/servicemenu.knsrc" because: "Config group not found! Check your KNS3 installation." org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.knewstuff.core: "Host download.kde.org not found" KNS backend error in backend "Color Schemes" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/colorschemes.knsrc" because: "Invalid Color Schemes backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "colorschemes.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" kns error "/etc/xdg/colorschemes.knsrc" "Invalid Color Schemes backend, contact your distributor." KNS backend error in backend "Aurorae Window Decorations" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/aurorae.knsrc" because: "Invalid Aurorae Window Decorations backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "aurorae.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/aurorae.knsrc" "Invalid Aurorae Window Decorations backend, contact your distributor." KNS backend error in backend "Plasma Widgets" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/plasmoids.knsrc" because: "Invalid Plasma Widgets backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "plasmoids.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/plasmoids.knsrc" "Invalid Plasma Widgets backend, contact your distributor." KNS backend error in backend "Icons" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/icons.knsrc" because: "Invalid Icons backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "icons.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/icons.knsrc" "Invalid Icons backend, contact your distributor." KNS backend error in backend "Window Manager Switching Layouts" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/kwinswitcher.knsrc" because: "Invalid Window Manager Switching Layouts backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "kwinswitcher.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/kwinswitcher.knsrc" "Invalid Window Manager Switching Layouts backend, contact your distributor." KNS backend error in backend "Cursors" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/xcursor.knsrc" because: "Invalid Cursors backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "xcursor.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/xcursor.knsrc" "Invalid Cursors backend, contact your distributor." KNS backend error in backend "Window Manager Effects" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/kwineffect.knsrc" because: "Invalid Window Manager Effects backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "kwineffect.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/kwineffect.knsrc" "Invalid Window Manager Effects backend, contact your distributor." KNS backend error in backend "Window Manager Scripts" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/kwinscripts.knsrc" because: "Invalid Window Manager Scripts backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "kwinscripts.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/kwinscripts.knsrc" "Invalid Window Manager Scripts backend, contact your distributor." KNS backend error in backend "Konsole" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/konsole.knsrc" because: "Invalid Konsole backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "konsole.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/konsole.knsrc" "Invalid Konsole backend, contact your distributor." KNS backend error in backend "Plasma Themes" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/plasma-themes.knsrc" because: "Invalid Plasma Themes backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "plasma-themes.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/plasma-themes.knsrc" "Invalid Plasma Themes backend, contact your distributor." KNS backend error in backend "Wallpapers" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/wallpaper.knsrc" because: "Invalid Wallpapers backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "wallpaper.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/wallpaper.knsrc" "Invalid Wallpapers backend, contact your distributor." KNS backend error in backend "Comics" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/comic.knsrc" because: "Invalid Comics backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "comic.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/comic.knsrc" "Invalid Comics backend, contact your distributor." KNS backend error in backend "Emoticons" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/emoticons.knsrc" because: "Invalid Emoticons backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "emoticons.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" Failed to refresh appstream metadata for flathub : Error updating appstream2: Unable to load summary from remote flathub: Error resolving “dl.flathub.org”: Temporary failure in name resolution; Error updating appstream: Unable to load summary from remote flathub: Error resolving “dl.flathub.org”: Temporary failure in name resolution org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) kns error "/etc/xdg/emoticons.knsrc" "Invalid Emoticons backend, contact your distributor." KNS backend error in backend "Wallpaper Plugins" : 4 "Loading of providers from file: https://download.kde.org/ocs/providers.xml failed" QVariant(QString, "https://download.kde.org/ocs/providers.xml") invalid kns backend! "/etc/xdg/wallpaperplugin.knsrc" because: "Invalid Wallpaper Plugins backend, contact your distributor." org.kde.plasma.libdiscover: Discarding invalid backend "wallpaperplugin.knsrc" org.kde.plasma.libdiscover: Couldn't find a category for "fwupd-backend" org.kde.plasma.libdiscover: last stream isn't over yet Filters(resourceUrl:QUrl("appstream://org.kde.krita"),) ResourcesProxyModel(0x5601d8d54ca0) KCrash: crashing... crashRecursionCounter = 2 KCrash: Application Name = plasma-discover path = /usr/bin pid = 27635 KCrash: Arguments: /usr/bin/plasma-discover KCrash: Attempting to start /usr/lib/x86_64-linux-gnu/libexec/drkonqi from kdeinit sock_file=/run/user/1000/kdeinit5__0 [1]+ Stopped plasma-discover
Git commit 8a6a4b2c566c97d41d9fb8eac5727b3ac3292651 by Aleix Pol. Committed on 26/11/2018 at 16:12. Pushed by apol into branch 'Plasma/5.14'. kns: fix crash upon removing a category Don't cache the last element in the list that is being cleared M +1 -1 libdiscover/Category/Category.cpp https://commits.kde.org/discover/8a6a4b2c566c97d41d9fb8eac5727b3ac3292651
*** Bug 403624 has been marked as a duplicate of this bug. ***
*** Bug 420804 has been marked as a duplicate of this bug. ***
*** Bug 420836 has been marked as a duplicate of this bug. ***
Git commit be9519bebffc36a068d6b85df1b3a90220b2d441 by Aleix Pol. Committed on 21/06/2020 at 01:47. Pushed by apol into branch 'Plasma/5.12'. kns: fix crash upon removing a category Don't cache the last element in the list that is being cleared Backported 8a6a4b2c566c97d41d9fb8eac5727b3ac3292651 to 5.12 since people seem to keep reporting it. FIXED-IN: 5.12 M +1 -1 libdiscover/Category/Category.cpp https://invent.kde.org/plasma/discover/commit/be9519bebffc36a068d6b85df1b3a90220b2d441
*** Bug 421731 has been marked as a duplicate of this bug. ***
*** Bug 422062 has been marked as a duplicate of this bug. ***
*** Bug 476850 has been marked as a duplicate of this bug. ***
Got a duplicate from Plasma 5.27.5 with the exact same backtrace and symptoms; re-opening. :(
Despire my re-opening this the other day, upon further investigation I think there's a very good chance it's fixed in Plasma 6 with a major refactor of how the KNS backend works, as I do see a lot of the backtrace is in KNS code that has been touched recently. As such, I'm going to mark this as fixed for now since unfortunately none of the Discover developers have been able to reproduce the original issue. However please do feel free to re-open this bug report if you can still reproduce it with the Plasma 6 Alpha (or beta, or final release). Thanks for understanding!