Bug 411286

I can confirm this behaviour also in 

Operating System: KDE neon Testing Edition
KDE Plasma Version: 5.16.5
KDE Frameworks Version: 5.62.0
Qt Version: 5.12.3
Kernel Version: 5.0.0-27-generic
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-3770 CPU @ 3.40GHz
Memory: 31,4 GiB

Unfortunately, the backtrace does not contain much information, other than that it is a crash inside the QML interpreter.

Pasting backtrace inline:

Thread 1 (Thread 0x7fae3b2fbe00 (LWP 4349)):
[KCrash Handler]
#6  0x0000000000000000 in ?? ()
#7  0x00007fae37450215 in QV4::Object::get (receiver=0x7fff56ecd6f8, hasProperty=0x0, name=0x7fff56ecd700, this=0x7fff56ecd6f8) at jsruntime/qv4object_p.h:308
#8  QV4::Lookup::getterProtoTwoClasses (l=<optimized out>, engine=<optimized out>, object=...) at jsruntime/qv4lookup.cpp:301
#9  0x00007fae1405560e in ?? ()

Created attachment 122709 [details]
New crash information added by DrKonqi

plasma-discover (5.16.5) using Qt 5.12.3

- What I was doing when the application crashed:

- Unusual behavior I noticed:

Application: plasma-discover (5.16.5)

Qt Version: 5.12.3
Frameworks Version: 5.62.0
Operating System: Linux 4.15.0-64-generic x86_64
Distribution: KDE neon User Edition 5.16

-- Information about the crash:
<Напишите подробно, что вы делали, когда произошла ошибка.>

The crash can be reproduced every time.

-- Backtrace:
Application: Центр программ 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 0x7ff34fc75e00 (LWP 4237))]

Thread 10 (Thread 0x7ff2b17fb700 (LWP 4258)):
#0  0x00007ff34a8a40f4 in __GI___libc_read (fd=54, buf=0x7ff2b17faba0, nbytes=16) at ../sysdeps/unix/sysv/linux/read.c:27
#1  0x00007ff344da32d0 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ff344d5e0b7 in g_main_context_check () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ff344d5e570 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ff344d5e6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ff344d5e721 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007ff344d86195 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#7  0x00007ff3476406db in start_thread (arg=0x7ff2b17fb700) at pthread_create.c:463
#8  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7ff2b3fff700 (LWP 4253)):
#0  0x00007ff3476469f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55a9668b32d4) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x55a9668b3280, cond=0x55a9668b32a8) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x55a9668b32a8, mutex=0x55a9668b3280) at pthread_cond_wait.c:655
#3  0x00007ff34afbcdbb in QWaitCondition::wait(QMutex*, QDeadlineTimer) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ff34afbd0c9 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff34e6536f8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007ff34e653b2a in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007ff3476406db in start_thread (arg=0x7ff2b3fff700) at pthread_create.c:463
#9  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7ff304b46700 (LWP 4252)):
#0  0x00007ff34a8a8bf9 in __GI___poll (fds=0x7ff30c004be0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ff344d5e5c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ff344d5e6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ff34b1ebdcb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ff34b18d03a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff34afb44ca in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007ff3476406db in start_thread (arg=0x7ff304b46700) at pthread_create.c:463
#8  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7ff316620700 (LWP 4245)):
#0  0x00007ff344d86680 in g_thread_self () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007ff344d5e6cd in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ff34b1ebdcb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3  0x00007ff34b18d03a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ff34afb44ca in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ff3476406db in start_thread (arg=0x7ff316620700) at pthread_create.c:463
#7  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7ff317c17700 (LWP 4244)):
#0  0x00007ff34a8a8bf9 in __GI___poll (fds=0x7ff310003ce0, nfds=1, timeout=9284) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ff344d5e5c9 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ff344d5e6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ff34b1ebdcb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ff34b18d03a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff34afb44ca in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007ff3476406db in start_thread (arg=0x7ff317c17700) at pthread_create.c:463
#8  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7ff321eab700 (LWP 4242)):
#0  0x00007ff3476469f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55a964893cb8) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  __pthread_cond_wait_common (abstime=0x0, mutex=0x55a964893c68, cond=0x55a964893c90) at pthread_cond_wait.c:502
#2  __pthread_cond_wait (cond=0x55a964893c90, mutex=0x55a964893c68) at pthread_cond_wait.c:655
#3  0x00007ff3232d00aa in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007ff3232cfdd7 in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007ff3476406db in start_thread (arg=0x7ff321eab700) at pthread_create.c:463
#6  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7ff3318cb700 (LWP 4241)):
#0  0x00007ff344da4664 in g_mutex_unlock () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007ff344d5e586 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ff344d5e6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ff34b1ebdcb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ff34b18d03a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff34afb44ca in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ff34bf9f115 in QQmlThreadPrivate::run (this=0x55a9647aa5a0) at qml/ftw/qqmlthread.cpp:148
#7  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007ff3476406db in start_thread (arg=0x7ff3318cb700) at pthread_create.c:463
#9  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7ff332adc700 (LWP 4240)):
#0  0x00007ff34b1ebb67 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#1  0x00007ff344d5dfe1 in g_main_context_check () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ff344d5e570 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ff344d5e6dc in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ff34b1ebdcb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff34b18d03a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ff34afb44ca in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007ff34c33d015 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#8  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x00007ff3476406db in start_thread (arg=0x7ff332adc700) at pthread_create.c:463
#10 0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7ff33a962700 (LWP 4239)):
#0  0x00007ff34a8a8bf9 in __GI___poll (fds=0x7ff33a961b68, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ff344493747 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007ff34449536a in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007ff33d542578 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007ff34afb5c72 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ff3476406db in start_thread (arg=0x7ff33a962700) at pthread_create.c:463
#6  0x00007ff34a8b588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7ff34fc75e00 (LWP 4237)):
[KCrash Handler]
#6  0x0000000000000000 in ?? ()
#7  0x00007ff34bdca215 in QV4::Object::get (receiver=0x7ffebdf59fc8, hasProperty=0x0, name=0x7ffebdf59fd0, this=0x7ffebdf59fc8) at jsruntime/qv4object_p.h:308
#8  QV4::Lookup::getterProtoTwoClasses (l=<optimized out>, engine=<optimized out>, object=...) at jsruntime/qv4lookup.cpp:301
#9  0x00007ff3280958ce in ?? ()
#10 0x0000000000000000 in ?? ()

Отправить на https://bugs.kde.org/

-- Backtrace (Reduced):
#7  0x00007ff34bdca215 in QV4::Object::get (receiver=0x7ffebdf59fc8, hasProperty=0x0, name=0x7ffebdf59fd0, this=0x7ffebdf59fc8) at jsruntime/qv4object_p.h:308
#8  QV4::Lookup::getterProtoTwoClasses (l=<optimized out>, engine=<optimized out>, object=...) at jsruntime/qv4lookup.cpp:301
[...]

*** Bug 412023 has been marked as a duplicate of this bug. ***

*** Bug 412032 has been marked as a duplicate of this bug. ***

*** Bug 412040 has been marked as a duplicate of this bug. ***

*** Bug 412050 has been marked as a duplicate of this bug. ***

*** Bug 412051 has been marked as a duplicate of this bug. ***

*** Bug 412056 has been marked as a duplicate of this bug. ***

Created attachment 122729 [details]
attachment-12285-0.html

Thanks. New, so a bit overwhelmed. Can further report that the crash occurs
when I click on Applications button. Hope this helps. best


On Thu, 19 Sep 2019, 12:05 pm Christoph Feck, <bugzilla_noreply@kde.org>
wrote:

> https://bugs.kde.org/show_bug.cgi?id=411286
>
> Christoph Feck <cfeck@kde.org> changed:
>
>            What    |Removed                     |Added
>
> ----------------------------------------------------------------------------
>                  CC|                            |tomcawley1@gmail.com
>
> --- Comment #9 from Christoph Feck <cfeck@kde.org> ---
> *** Bug 412056 has been marked as a duplicate of this bug. ***
>
> --
> You are receiving this mail because:
> You are on the CC list for the bug.

I have been able to reproduce only with Qt 5.12.3 and frameworks 5.62.
https://invent.kde.org/snippets/461
https://invent.kde.org/snippets/462

Here's backtraces with JIT disabled. Looks a lot like a crash on Qt.

Sounds like https://bugreports.qt.io/browse/QTBUG-75203, which got fixed in Qt 5.12.4.

When I uninstalled the plasma-discover-backend-flatpak package the crash does not happen anymore.  

This is my first bug report.  Sorry if it is incomplete. I hope it is helpful.

*** Bug 412142 has been marked as a duplicate of this bug. ***

*** Bug 412138 has been marked as a duplicate of this bug. ***

*** Bug 412136 has been marked as a duplicate of this bug. ***

*** Bug 412133 has been marked as a duplicate of this bug. ***

*** Bug 412158 has been marked as a duplicate of this bug. ***

*** Bug 412183 has been marked as a duplicate of this bug. ***

I don't know if it may help but discover failed to get some metadata from flatpak, it search in an empty folder

Console Output:

adding empty sources model QStandardItemModel(0x55d7f6768cc0)
no packages for "org.kde.plasma.quicklaunch"
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.plasma.diskquota"
no packages for "org.kde.plasma.timer"
no packages for "org.kde.kscreen"
no packages for "org.gnupg.scdaemon"
no packages for "org.kde.plasma.appmenu"
no packages for "im.riot.webapp"
no packages for "org.kde.plasma.kimpanel"
no packages for "org.cockpit_project.cockpit"
invalid kns backend! "/usr/share/knsrcfiles/ksysguard.knsrc" because: "Config group not found! Check your KNS3 installation."
no org.freedesktop.Platform.GL.nvidia-418-56
Failed to parse appstream metadata: AppStream::Metadata::MetadataErrorParse "/var/lib/flatpak/exports/share/applications/org.freedesktop.Platform.GL.nvidia-418-56.desktop"
no org.freedesktop.Platform.GL.nvidia-430-40
Failed to parse appstream metadata: AppStream::Metadata::MetadataErrorParse "/var/lib/flatpak/exports/share/applications/org.freedesktop.Platform.GL.nvidia-430-40.desktop"
no org.freedesktop.Platform.GL.nvidia-430-50
Failed to parse appstream metadata: AppStream::Metadata::MetadataErrorParse "/var/lib/flatpak/exports/share/applications/org.freedesktop.Platform.GL.nvidia-430-50.desktop"
no org.freedesktop.Platform.html5-codecs
Failed to parse appstream metadata: AppStream::Metadata::MetadataErrorParse "/var/lib/flatpak/exports/share/applications/org.freedesktop.Platform.html5-codecs.desktop"
took really long to fetch PackageKitBackend(0x55d7f5fbe0b0)
took really long to fetch KNSBackend(0x55d7f83195e0, name = "/usr/share/knsrcfiles/cgctheme.knsrc")
took really long to fetch KNSBackend(0x55d7f80466f0, name = "/usr/share/knsrcfiles/comic.knsrc")
took really long to fetch KNSBackend(0x55d7f8712590, name = "/usr/share/knsrcfiles/emoticons.knsrc")
took really long to fetch KNSBackend(0x55d7f8041390, name = "/usr/share/knsrcfiles/cgcgtk3.knsrc")
took really long to fetch KNSBackend(0x55d7f803cb70, name = "/usr/share/knsrcfiles/konsole.knsrc")
took really long to fetch KNSBackend(0x55d7f8040d60, name = "/usr/share/knsrcfiles/kwineffect.knsrc")
took really long to fetch KNSBackend(0x55d7f84eae00, name = "/usr/share/knsrcfiles/aurorae.knsrc")
took really long to fetch KNSBackend(0x55d7f831be50, name = "/usr/share/knsrcfiles/discover_ktexteditor_codesnippets_core.knsrc")
took really long to fetch KNSBackend(0x55d7f83e52b0, name = "/usr/share/knsrcfiles/xcursor.knsrc")
qrc:/qml/ApplicationsListPage.qml:144:16: QML ResourcesProxyModel: Binding loop detected for property "sortOrder"
KCrash: crashing... crashRecursionCounter = 2
KCrash: Application Name = plasma-discover path = /usr/bin pid = 14510
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

I just filed a bug that was just like this a few hours ago. I'm wondering, is this after a fresh install (and just updating, and nothing more)? Or had you changed any kind of settings or anything? 
  In my instance, the only things that I can recall having done was I removed the -xorg.org.input.libinput- packages from my machine, because they broke the touch screen on my HP TouchSmart. I am guessing that it reverted back to evdev. But, I wonder if it could have anything to do with this bug.

Here is a full back trace using gdb, and reproducing the crash:

    GNU gdb (Ubuntu 8.1-0ubuntu3) 8.1.0.20180409-git
Copyright (C) 2018 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from plasma-discover...Reading symbols from /usr/lib/debug/.build-id/fc/5dbb5889066a0e46f3104784a591182c73d029.debug...done.
done.
(gdb) run
Starting program: /usr/bin/plasma-discover 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffe2dce700 (LWP 5172)]
[New Thread 0x7fffdaf02700 (LWP 5173)]
[New Thread 0x7fffd9cf1700 (LWP 5174)]
[New Thread 0x7fffc5ba4700 (LWP 5175)]
adding empty sources model QStandardItemModel(0x55555604db40)
no packages for "org.kde.plasma.quicklaunch"
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.plasma.diskquota"
no packages for "org.kde.plasma.timer"
no packages for "org.kde.kscreen"
no packages for "org.kde.plasma.appmenu"
no packages for "im.riot.webapp"
no packages for "org.kde.plasma.kimpanel"
no packages for "org.cockpit_project.cockpit"
[New Thread 0x7fff98a57700 (LWP 5177)]
[New Thread 0x7fff9344a700 (LWP 5178)]
[New Thread 0x7fff92c49700 (LWP 5179)]
[New Thread 0x7fff9203e700 (LWP 5180)]
invalid kns backend! "/usr/share/knsrcfiles/ksysguard.knsrc" because: "Config group not found! Check your KNS3 installation."
took really long to fetch PackageKitBackend(0x555555955100)
[New Thread 0x7fff9115e700 (LWP 5189)]
[New Thread 0x7fff9095d700 (LWP 5190)]
QNetworkReplyImpl: setCachingEnabled(true) called after setCachingEnabled(false)
took really long to fetch KNSBackend(0x555557a5e440, name = "/usr/share/knsrcfiles/cgctheme.knsrc")
qrc:/qml/ApplicationsListPage.qml:144:16: QML ResourcesProxyModel: Binding loop detected for property "sortOrder"

Thread 1 "plasma-discover" received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) thread apply all backtrace

Thread 11 (Thread 0x7fff9095d700 (LWP 5190)):
#0  0x00007fffef980ed9 in futex_reltimed_wait_cancelable (private=<optimized out>, reltime=0x7fff9095caa0, expected=0, futex_word=0x7fff8c007160)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  0x00007fffef980ed9 in __pthread_cond_wait_common (abstime=0x7fff9095cb60, mutex=0x7fff8c007110, cond=0x7fff8c007138) at pthread_cond_wait.c:533
#2  0x00007fffef980ed9 in __pthread_cond_timedwait (cond=0x7fff8c007138, mutex=0x7fff8c007110, abstime=0x7fff9095cb60) at pthread_cond_wait.c:667
#3  0x00007ffff32f6d36 in QWaitCondition::wait(QMutex*, QDeadlineTimer) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff32f7096 in QWaitCondition::wait(QMutex*, unsigned long) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32f4740 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fffef97a6db in start_thread (arg=0x7fff9095d700)
    at pthread_create.c:463
#8  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 10 (Thread 0x7fff9115e700 (LWP 5189)):
#0  0x00007ffff2be2bf9 in __GI___poll (fds=0x7fff88001990, nfds=1, timeout=129904) at ../sysdeps/unix/sysv/linux/poll.c:29
---Type <return> to continue, or q <return> to quit---
#1  0x00007fffed0985c9 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffed0986dc in g_main_context_iteration ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff3525daf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff34c703a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32ee4ca in QThread::exec() ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fffef97a6db in start_thread (arg=0x7fff9115e700)
    at pthread_create.c:463
#8  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7fff9203e700 (LWP 5180)):
#0  0x00007fffef980ed9 in futex_reltimed_wait_cancelable (private=<optimized out>, reltime=0x7fff9203daa0, expected=0, futex_word=0x7fff8c0053b0)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  0x00007fffef980ed9 in __pthread_cond_wait_common (abstime=0x7fff9203db60, mutex=0x7fff8c005360, cond=0x7fff8c005388) at pthread_cond_wait.c:533
#2  0x00007fffef980ed9 in __pthread_cond_timedwait (cond=0x7fff8c005388, mutex=0x7fff8c005360, abstime=0x7fff9203db60) at pthread_cond_wait.c:667
---Type <return> to continue, or q <return> to quit---
#3  0x00007ffff32f6d36 in QWaitCondition::wait(QMutex*, QDeadlineTimer) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff32f7096 in QWaitCondition::wait(QMutex*, unsigned long) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32f4740 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fffef97a6db in start_thread (arg=0x7fff9203e700)
    at pthread_create.c:463
#8  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7fff92c49700 (LWP 5179)):
#0  0x00007fffef980ed9 in futex_reltimed_wait_cancelable (private=<optimized out>, reltime=0x7fff92c48aa0, expected=0, futex_word=0x7fff8c003474)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:142
#1  0x00007fffef980ed9 in __pthread_cond_wait_common (abstime=0x7fff92c48b60, mutex=0x7fff8c003420, cond=0x7fff8c003448) at pthread_cond_wait.c:533
#2  0x00007fffef980ed9 in __pthread_cond_timedwait (cond=0x7fff8c003448, mutex=0x7fff8c003420, abstime=0x7fff92c48b60) at pthread_cond_wait.c:667
#3  0x00007ffff32f6d36 in QWaitCondition::wait(QMutex*, QDeadlineTimer) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff32f7096 in QWaitCondition::wait(QMutex*, unsigned long) ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
---Type <return> to continue, or q <return> to quit---
#5  0x00007ffff32f4740 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fffef97a6db in start_thread (arg=0x7fff92c49700)
    at pthread_create.c:463
#8  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7fff9344a700 (LWP 5178)):
#0  0x00007ffff2be2bf9 in __GI___poll (fds=0x7fff8c1c60e0, nfds=1, timeout=127479) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fffed0985c9 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffed0986dc in g_main_context_iteration ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff3525daf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff34c703a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32ee4ca in QThread::exec() ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fffef97a6db in start_thread (arg=0x7fff9344a700)
    at pthread_create.c:463
#8  0x00007ffff2bef88f in clone ()
---Type <return> to continue, or q <return> to quit---
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7fff98a57700 (LWP 5177)):
#0  0x00007ffff2be2bf9 in __GI___poll (fds=0x7fff940018d0, nfds=1, timeout=9627) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fffed0985c9 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffed0986dc in g_main_context_iteration ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff3525daf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff34c703a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32ee4ca in QThread::exec() ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007fffef97a6db in start_thread (arg=0x7fff98a57700)
    at pthread_create.c:463
#8  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7fffc5ba4700 (LWP 5175)):
#0  0x00007fffef9809f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x555555a256d8)
---Type <return> to continue, or q <return> to quit---
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1  0x00007fffef9809f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x555555a25688, cond=0x555555a256b0) at pthread_cond_wait.c:502
#2  0x00007fffef9809f3 in __pthread_cond_wait (cond=0x555555a256b0, mutex=0x555555a25688) at pthread_cond_wait.c:655
#3  0x00007fffcb6c923a in  () at /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#4  0x00007fffcb6c8f67 in  () at /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#5  0x00007fffef97a6db in start_thread (arg=0x7fffc5ba4700)
    at pthread_create.c:463
#6  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7fffd9cf1700 (LWP 5174)):
#0  0x00007ffff2be2bf9 in __GI___poll (fds=0x7fffcc004a00, nfds=1, timeout=-1)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fffed0985c9 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffed0986dc in g_main_context_iteration ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff3525daf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff34c703a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32ee4ca in QThread::exec() ()
---Type <return> to continue, or q <return> to quit---
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff42d9115 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fffef97a6db in start_thread (arg=0x7fffd9cf1700)
    at pthread_create.c:463
#9  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7fffdaf02700 (LWP 5173)):
#0  0x00007ffff2be2bf9 in __GI___poll (fds=0x7fffd4018040, nfds=4, timeout=-1)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fffed0985c9 in  () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffed0986dc in g_main_context_iteration ()
    at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff3525daf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff34c703a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff32ee4ca in QThread::exec() ()
    at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff4677015 in  () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007fffef97a6db in start_thread (arg=0x7fffdaf02700)
---Type <return> to continue, or q <return> to quit---
    at pthread_create.c:463
#9  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7fffe2dce700 (LWP 5172)):
#0  0x00007ffff2be2bf9 in __GI___poll (fds=0x7fffe2dcdb68, nfds=1, timeout=-1)
    at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fffec7cd747 in  () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fffec7cf36a in xcb_wait_for_event ()
    at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fffe59ae578 in  () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007ffff32efc72 in  () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007fffef97a6db in start_thread (arg=0x7fffe2dce700)
    at pthread_create.c:463
#6  0x00007ffff2bef88f in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7ffff7fade00 (LWP 5168)):
#0  0x0000000000000000 in  ()
#1  0x00007ffff4104215 in  () at /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#2  0x00007fffd810c8ce in  ()
#3  0x0000000000000000 in  ()

Created attachment 122800 [details]
attachment-4881-0.html

Yes - it was a fresh install, but I hadn't changed much in the system. The
only problem now is when I try to access the menu buttons -
"applications",  etc. I installed synaptic &  used alt-get in command line
to get other packages.  Discover is providing updates.

Maybe try updating via command line, and use synaptic utilities?

Best of luck.

On Sun, 22 Sep 2019, 3:20 pm Chris, <bugzilla_noreply@kde.org> wrote:

> https://bugs.kde.org/show_bug.cgi?id=411286
>
> --- Comment #21 from Chris <christopherbwilliams1990@gmail.com> ---
> I just filed a bug that was just like this a few hours ago. I'm wondering,
> is
> this after a fresh install (and just updating, and nothing more)? Or had
> you
> changed any kind of settings or anything?
>   In my instance, the only things that I can recall having done was I
> removed
> the -xorg.org.input.libinput- packages from my machine, because they broke
> the
> touch screen on my HP TouchSmart. I am guessing that it reverted back to
> evdev.
> But, I wonder if it could have anything to do with this bug.
>
> --
> You are receiving this mail because:
> You are on the CC list for the bug.

(In reply to David Berry from comment #13)
> When I uninstalled the plasma-discover-backend-flatpak package the crash
> does not happen anymore.  
> 
> This is my first bug report.  Sorry if it is incomplete. I hope it is
> helpful.

I just did that and the crush also does not happen. Thank you!
Still, I have the icon in the tray that signals that there is some updates available, in spite of the fact that there are no updates.

For your information: I also uninstalled the package xorg.org.input.libinput-packages before, because it does not support the specific button for double-clicking the RollerMouse.

(In reply to tom cawley from comment #23)
> Created attachment 122800 [details]
> attachment-4881-0.html
> 
> Yes - it was a fresh install, but I hadn't changed much in the system. The
> only problem now is when I try to access the menu buttons -
> "applications",  etc. I installed synaptic &  used alt-get in command line
> to get other packages.  Discover is providing updates.
> 
> Maybe try updating via command line, and use synaptic utilities?
> 
> Best of luck.

Yeah, thats what is going on with mine. When I click on the categories like applications and what not, it crashes.

I installed KDEneon yesterday.
Used the latest build.

Discover crashes every time as reported by all others here.

I installed synaptic and was able to install software I need.

Then I downloaded a deb-file of google-chrome-browser and double clicked it.
Discover opened the deb-file and asked for my root-password.
I gave it and Discover installed the browser successfully.

I then clicked on "applications" in Discover and it did not crash.
I was able to browse all applications with Discover and install some apps.

After closing Discover and starting it again, the crash ist there again.

Please test qtdeclarative from the /release/ repo, edit /etc/apt/sources.list.d/neon.list replace /user/ with /release/ and apt update; apt full-upgrade  let me know if that helps

(In reply to Fabian Vogt from comment #12)
> Sounds like https://bugreports.qt.io/browse/QTBUG-75203, which got fixed in
> Qt 5.12.4.

Sounds quite likely.

In Kubuntu 19.04, with backports, so Qt 5.12.2, FW 5.62.0 and Plasma 5.16.5 = NOCRASH

In Kubuntu 19.10, so Qt 5.12.4, FW 5.62.0 and Plasma 5.16.5 = NOCRASH

Reassigning. This bug only exists in neon, Discover on other distros is not affected.

It is likely possible to workaround this bug only present in outdated Qt versions in Discover (like it was done in p-w for a similar crash), but Qt needs to be fixed anyway to avoid hitting this crash in other applications.

*** Bug 412203 has been marked as a duplicate of this bug. ***

*** Bug 412196 has been marked as a duplicate of this bug. ***

(In reply to Jonathan Riddell from comment #28)
> Please test qtdeclarative from the /release/ repo, edit
> /etc/apt/sources.list.d/neon.list replace /user/ with /release/ and apt
> update; apt full-upgrade  let me know if that helps

Did not crash on starting and finding updates here, but still get the same crash on clicking LHS categories.

(In reply to Rik Mills from comment #33)
> Did not crash on starting and finding updates here.

Correction. It does crash. Must have been impatient and not waited long enough on 1st try.

(In reply to Jonathan Riddell from comment #28)
> Please test qtdeclarative from the /release/ repo, edit
> /etc/apt/sources.list.d/neon.list replace /user/ with /release/ and apt
> update; apt full-upgrade  let me know if that helps

So far it worked perfectly what you've said.
Thank you very much.

Operating System: KDE neon 5.16
KDE Plasma Version: 5.16.5
KDE Frameworks Version: 5.62.0
Qt Version: 5.12.3
Kernel Version: 5.0.0-29-generic
OS Type: 64-bit
Processors: 4 × AMD A10-7850K Radeon R7, 12 Compute Cores 4C+8G
Memory: 14,7 GiB

Yes, the qtdeclarative in /release got some extra patches since my 1st test (build38). Now the crash seems fixed with that version (build39).

https://packaging.neon.kde.org/qt/qtdeclarative.git/commit/?id=66c7a32a81d12c2180566abd34a8acb13ca1ef45

Fix should be available in all neon editions.

To update use `pkcon refresh && pkcon update`.

I Just want to say thank you... I see now... when I get some money you'll get some too. Over this passed year I've added Neon to my main puters and to my Wife puter as well... You Rock keep up the good work and Thank you... Thank you... Thank you.

Created attachment 122820 [details]
attachment-3319-0.html

Just uploaded updates & Discover now fully functional.  Great and much
thanks.  KDE's the best.

On Mon, 23 Sep 2019, 1:32 pm Rik Mills, <bugzilla_noreply@kde.org> wrote:

> https://bugs.kde.org/show_bug.cgi?id=411286
>
> --- Comment #36 from Rik Mills <rikmills@kubuntu.org> ---
> Yes, the qtdeclarative in /release got some extra patches since my 1st test
> (build38). Now the crash seems fixed with that version (build39).
>
> --
> You are receiving this mail because:
> You are on the CC list for the bug.

I can confirm now Discover works again smoothly.

Thanks to all great developers. :)

SOFTWARE/OS VERSIONS

Operating System: KDE neon Testing Edition
KDE Plasma Version: 5.16.90
KDE Frameworks Version: 5.63.0
Qt Version: 5.12.3
Kernel Version: 5.0.0-30-generic
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-3770 CPU @ 3.40GHz
Memory: 31,4 GiB

I can also confirm now Discover works again smoothly.

Thanks to all great developers for the fast fix!

(In reply to ludger from comment #41)
> I can also confirm now Discover works again smoothly.
> 
> Thanks to all great developers for the fast fix!

To be completely fair, Qt 5.12.4 was out in June, so the fix was already available for quite a while. Most other distros with the exception of Neon (of which this bug belongs to) had already a non-affected Qt version and thus suffered no crash.

*** Bug 412033 has been marked as a duplicate of this bug. ***

*** Bug 412197 has been marked as a duplicate of this bug. ***