Application: plasmashell (5.5.5)

Qt Version: 5.5.1
Operating System: Linux 4.4.0-21-generic x86_64
Distribution: Ubuntu 16.04 LTS

-- Information about the crash:
- What I was doing when the application crashed:
Right-clicked on the audio settings applet and selected 'Audio Volume Settings...'

- Unusual behavior I noticed:
Plasma crashed

This has been happening since the update from Kubuntu 15.10 -> Kubuntu 16.04

Bluetooth headset connected (Plantronics Backbeat Pro) and has been working for around a year or so. Since I upgraded OS (using upgrade path, not a fresh install) no audio comes through to the headphones and the second time I go into Volume Settings as mentioned above, plasma crashes.

I attempted to mark this as a duplicate of #362432 in the bug reporting tool, but it wouldn't let me - I selected that it was a duplicate but it did not seem to actually mark it as a duplicate and told me I hadn't marked any as duplicates.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fd0b6a9d8c0 (LWP 2063))]

Thread 10 (Thread 0x7fd0a1dbf700 (LWP 2089)):
#0  0x00007fd0b11aee8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fd0b5273c62 in _xcb_conn_wait (__timeout=-1, __nfds=1, __fds=0x7fd0a1dbec00) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#2  0x00007fd0b5273c62 in _xcb_conn_wait (c=c@entry=0x23e2200, cond=cond@entry=0x23e2240, vector=vector@entry=0x0, count=count@entry=0x0) at ../../src/xcb_conn.c:459
#3  0x00007fd0b52758d7 in xcb_wait_for_event (c=0x23e2200) at ../../src/xcb_in.c:693
#4  0x00007fd0a3f0d629 in QXcbEventReader::run() (this=0x23ec8c0) at qxcbconnection.cpp:1253
#5  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x23ec8c0) at thread/qthread_unix.cpp:331
#6  0x00007fd0b09916fa in start_thread (arg=0x7fd0a1dbf700) at pthread_create.c:333
#7  0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 9 (Thread 0x7fd09b3ea700 (LWP 2101)):
#0  0x00007fd0b11aee8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fd0adf4431c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7fd094003070, timeout=<optimized out>, context=0x7fd094000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007fd0adf4431c in g_main_context_iterate (context=context@entry=0x7fd094000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3835
#3  0x00007fd0adf4442c in g_main_context_iteration (context=0x7fd094000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fd0940008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fd09b3e9ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fd0b189f8a4 in QThread::exec() (this=this@entry=0x24c5ec0) at thread/qthread.cpp:503
#7  0x00007fd0b41473c5 in QQmlThreadPrivate::run() (this=0x24c5ec0) at qml/ftw/qqmlthread.cpp:141
#8  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x24c5ec0) at thread/qthread_unix.cpp:331
#9  0x00007fd0b09916fa in start_thread (arg=0x7fd09b3ea700) at pthread_create.c:333
#10 0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 8 (Thread 0x7fd08ffcd700 (LWP 2113)):
#0  0x00007fd0b11aee8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fd0adf4431c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7fd088002e70, timeout=<optimized out>, context=0x7fd088000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007fd0adf4431c in g_main_context_iterate (context=context@entry=0x7fd088000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3835
#3  0x00007fd0adf4442c in g_main_context_iteration (context=0x7fd088000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fd0880008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fd08ffccce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fd0b189f8a4 in QThread::exec() (this=this@entry=0x27fe6c0) at thread/qthread.cpp:503
#7  0x00007fd0b41473c5 in QQmlThreadPrivate::run() (this=0x27fe6c0) at qml/ftw/qqmlthread.cpp:141
#8  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x27fe6c0) at thread/qthread_unix.cpp:331
#9  0x00007fd0b09916fa in start_thread (arg=0x7fd08ffcd700) at pthread_create.c:333
#10 0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7fd08e13b700 (LWP 2115)):
#0  0x00007fd0adf88a64 in g_mutex_unlock (mutex=0x7fd080000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gthread-posix.c:1350
#1  0x00007fd0adf438a0 in g_main_context_prepare (context=context@entry=0x7fd080000990, priority=priority@entry=0x7fd08e13abb0) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3440
#2  0x00007fd0adf4424b in g_main_context_iterate (context=context@entry=0x7fd080000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3820
#3  0x00007fd0adf4442c in g_main_context_iteration (context=0x7fd080000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fd0800008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fd08e13ace0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fd0b189f8a4 in QThread::exec() (this=this@entry=0x28d3b90) at thread/qthread.cpp:503
#7  0x00007fd0b41473c5 in QQmlThreadPrivate::run() (this=0x28d3b90) at qml/ftw/qqmlthread.cpp:141
#8  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x28d3b90) at thread/qthread_unix.cpp:331
#9  0x00007fd0b09916fa in start_thread (arg=0x7fd08e13b700) at pthread_create.c:333
#10 0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7fd08c9d4700 (LWP 2134)):
#0  0x00007fd0b09973a0 in pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fd0b64ecbd4 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007fd0b64ecc19 in  () at /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007fd0b09916fa in start_thread (arg=0x7fd08c9d4700) at pthread_create.c:333
#4  0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7fd085fb4700 (LWP 2152)):
#0  0x00007fd0b11aa9cd in read () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fd0adf876c0 in g_wakeup_acknowledge (__nbytes=16, __buf=0x7fd085fb3a90, __fd=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/unistd.h:44
#2  0x00007fd0adf876c0 in g_wakeup_acknowledge (wakeup=0x7fd080002780) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gwakeup.c:210
#3  0x00007fd0adf43e04 in g_main_context_check (context=context@entry=0x7fcffc000990, max_priority=2147483647, fds=fds@entry=0x7fcffc003120, n_fds=n_fds@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3632
#4  0x00007fd0adf442c0 in g_main_context_iterate (context=context@entry=0x7fcffc000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3837
#5  0x00007fd0adf4442c in g_main_context_iteration (context=0x7fcffc000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#6  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fcffc0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#7  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fd085fb3c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#8  0x00007fd0b189f8a4 in QThread::exec() (this=this@entry=0x2b2aa40) at thread/qthread.cpp:503
#9  0x00007fd0b4acded6 in QQuickPixmapReader::run() (this=0x2b2aa40) at util/qquickpixmapcache.cpp:817
#10 0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x2b2aa40) at thread/qthread_unix.cpp:331
#11 0x00007fd0b09916fa in start_thread (arg=0x7fd085fb4700) at pthread_create.c:333
#12 0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fcfef5b8700 (LWP 2467)):
#0  0x00007fd0b11aee8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fd0adf4431c in g_main_context_iterate (priority=2147483647, n_fds=1, fds=0x7fcfe80048c0, timeout=<optimized out>, context=0x7fcfe8000990) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:4135
#2  0x00007fd0adf4431c in g_main_context_iterate (context=context@entry=0x7fcfe8000990, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3835
#3  0x00007fd0adf4442c in g_main_context_iteration (context=0x7fcfe8000990, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#4  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fcfe80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fcfef5b7cc0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fd0b189f8a4 in QThread::exec() (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007fcff1a987d7 in KCupsConnection::run() () at /usr/lib/x86_64-linux-gnu/libkcupslib.so
#8  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x4cb7f80) at thread/qthread_unix.cpp:331
#9  0x00007fd0b09916fa in start_thread (arg=0x7fcfef5b8700) at pthread_create.c:333
#10 0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fcfe2385700 (LWP 3905)):
#0  0x00007fd0adf88a49 in g_mutex_lock (mutex=mutex@entry=0x7fcfd422a350) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gthread-posix.c:1338
#1  0x00007fd0adf442de in g_main_context_iterate (context=context@entry=0x7fcfd422a350, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3844
#2  0x00007fd0adf4442c in g_main_context_iteration (context=0x7fcfd422a350, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#3  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fcfd40d9670, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fcfe2384ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007fd0b189f8a4 in QThread::exec() (this=this@entry=0x5755f00) at thread/qthread.cpp:503
#6  0x00007fd0b41473c5 in QQmlThreadPrivate::run() (this=0x5755f00) at qml/ftw/qqmlthread.cpp:141
#7  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x5755f00) at thread/qthread_unix.cpp:331
#8  0x00007fd0b09916fa in start_thread (arg=0x7fcfe2385700) at pthread_create.c:333
#9  0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fcfe3791700 (LWP 3906)):
#0  0x00007fd0adf6aff9 in g_thread_self () at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gthread.c:993
#1  0x00007fd0adf4441d in g_main_context_iteration (context=0x7fcfdc1ce450, may_block=may_block@entry=1) at /build/glib2.0-t9oPgV/glib2.0-2.48.0/./glib/gmain.c:3901
#2  0x00007fd0b1adba9b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7fcfdc0df3d0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#3  0x00007fd0b1a82dea in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fcfe3790ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#4  0x00007fd0b189f8a4 in QThread::exec() (this=this@entry=0x5941060) at thread/qthread.cpp:503
#5  0x00007fd0b41473c5 in QQmlThreadPrivate::run() (this=0x5941060) at qml/ftw/qqmlthread.cpp:141
#6  0x00007fd0b18a484e in QThreadPrivate::start(void*) (arg=0x5941060) at thread/qthread_unix.cpp:331
#7  0x00007fd0b09916fa in start_thread (arg=0x7fcfe3791700) at pthread_create.c:333
#8  0x00007fd0b11bab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fd0b6a9d8c0 (LWP 2063)):
[KCrash Handler]
#6  0x00007fd0b40606d5 in QV4::Heap::StringObject::StringObject(QV4::ExecutionEngine*, QV4::Value const&) (this=0x0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qrefcount.h:54
#7  0x00007fd0b40606d5 in QV4::Heap::StringObject::StringObject(QV4::ExecutionEngine*, QV4::Value const&) (this=<optimized out>) at jsruntime/qv4string_p.h:84
#8  0x00007fd0b40606d5 in QV4::Heap::StringObject::StringObject(QV4::ExecutionEngine*, QV4::Value const&) (this=<optimized out>) at jsruntime/qv4string_p.h:145
#9  0x00007fd0b40606d5 in QV4::Heap::StringObject::StringObject(QV4::ExecutionEngine*, QV4::Value const&) (this=<optimized out>, engine=0x599f8c0, val=...) at jsruntime/qv4stringobject.cpp:91
#10 0x00007fd0b4007685 in QV4::ExecutionEngine::newStringObject(QV4::Value const&) (arg2=..., arg1=0x599f8c0, this=<optimized out>) at jsruntime/qv4mm_p.h:126
#11 0x00007fd0b4007685 in QV4::ExecutionEngine::newStringObject(QV4::Value const&) (this=0x599f8c0, value=...) at jsruntime/qv4engine.cpp:557
#12 0x00007fd0b40a08b2 in QV4::Runtime::getProperty(QV4::ExecutionEngine*, QV4::Value const&, int) (engine=0x599f8c0, object=..., nameIndex=<optimized out>) at jsruntime/qv4runtime.cpp:686
#13 0x00007fcfe124d509 in  ()
#14 0x00007fcfe1366378 in  ()
#15 0x00007fcfe1366378 in  ()
#16 0x0000000000000000 in  ()

Possible duplicates by query: bug 362432, bug 359367, bug 356925, bug 356897, bug 356856.

Reported using DrKonqi