I re-compile Akonadi from source some hours before this crash. My current head is: bf2fddd8ecb9a8e3ec8d50d8371b651e1c1e3406

I found many bugs related with this assert in "createItemSyncInstanceIfMissing" but it seems that none is related with this code path. Sorry if this report is duplicate.

Application: akonadi_googlecalendar_resource (akonadi_googlecalendar_resource), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f70c61d8940 (LWP 3099))]

Thread 5 (Thread 0x7f70c40c8700 (LWP 3127)):
#0  0x00007f70dcfaf5ad in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007f70d4d0ec62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007f70d4d108d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007f70c5def4a9 in QXcbEventReader::run (this=0x920010) at qxcbconnection.cpp:1253
#4  0x00007f70dd8bb7fe in QThreadPrivate::start (arg=0x920010) at thread/qthread_unix.cpp:331
#5  0x00007f70d46e36fa in start_thread (arg=0x7f70c40c8700) at pthread_create.c:333
#6  0x00007f70dcfbb2dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f70c2b35700 (LWP 3160)):
#0  socketNotifierSourceCheck (source=0x7f70b4002e00) at kernel/qeventdispatcher_glib.cpp:74
#1  0x00007f70d41c1d61 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f70d41c22d0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f70d41c243c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f70ddaf2a6b in QEventDispatcherGlib::processEvents (this=0x7f70b40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f70dda99d7a in QEventLoop::exec (this=this@entry=0x7f70c2b34c80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f70dd8b6854 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f70dd8bb7fe in QThreadPrivate::start (arg=0x9a2790) at thread/qthread_unix.cpp:331
#8  0x00007f70d46e36fa in start_thread (arg=0x7f70c2b35700) at pthread_create.c:333
#9  0x00007f70dcfbb2dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f70c2334700 (LWP 3170)):
#0  0x00007f70d4206a94 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f70d41c224e in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f70d41c243c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f70ddaf2a6b in QEventDispatcherGlib::processEvents (this=0x7f70b80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f70dda99d7a in QEventLoop::exec (this=this@entry=0x7f70c2333c80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f70dd8b6854 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007f70dd8bb7fe in QThreadPrivate::start (arg=0x99cbc0) at thread/qthread_unix.cpp:331
#7  0x00007f70d46e36fa in start_thread (arg=0x7f70c2334700) at pthread_create.c:333
#8  0x00007f70dcfbb2dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f70c1b33700 (LWP 3237)):
#0  0x00007f70d41c1c7f in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f70d41c22d0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f70d41c243c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f70ddaf2a6b in QEventDispatcherGlib::processEvents (this=0x7f70ac0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f70dda99d7a in QEventLoop::exec (this=this@entry=0x7f70c1b32c80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f70dd8b6854 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#6  0x00007f70dd8bb7fe in QThreadPrivate::start (arg=0x9a87d0) at thread/qthread_unix.cpp:331
#7  0x00007f70d46e36fa in start_thread (arg=0x7f70c1b33700) at pthread_create.c:333
#8  0x00007f70dcfbb2dd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f70c61d8940 (LWP 3099)):
[KCrash Handler]
#6  0x00007f70dcee9518 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
#7  0x00007f70dceeb0ea in __GI_abort () at abort.c:89
#8  0x00007f70dd8a8fb1 in qt_message_fatal (context=..., message=<synthetic pointer>) at global/qlogging.cpp:1578
#9  QMessageLogger::fatal (this=this@entry=0x7ffee00e0bd0, msg=msg@entry=0x7f70ddb66028 "ASSERT failure in %s: \"%s\", file %s, line %d") at global/qlogging.cpp:781
#10 0x00007f70dd8a4181 in qt_assert_x (where=<optimized out>, what=<optimized out>, file=<optimized out>, line=<optimized out>) at global/qglobal.cpp:2974
#11 0x00007f70e0ed5dfc in Akonadi::ResourceBasePrivate::createItemSyncInstanceIfMissing (this=0x97c4f0) at /media/karry/data/src/akonadi/src/agentbase/resourcebase.cpp:184
#12 0x00007f70e0ed22d2 in Akonadi::ResourceBase::itemsRetrievedIncremental (this=0x985ed0, changedItems=..., removedItems=...) at /media/karry/data/src/akonadi/src/agentbase/resourcebase.cpp:1277
#13 0x0000000000417ea1 in CalendarResource::slotItemsRetrieved (this=0x985ed0, job=0xaacd10) at /media/karry/data/src/kdepim-runtime/resources/google/calendar/calendarresource.cpp:595
#14 0x0000000000429c20 in QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<KGAPI2::Job*>, void, void (CalendarResource::*)(KGAPI2::Job*)>::call (f=(void (CalendarResource::*)(CalendarResource * const, KGAPI2::Job *)) 0x4171f8 <CalendarResource::slotItemsRetrieved(KGAPI2::Job*)>, o=0x985ed0, arg=0x7ffee00e1130) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:501
#15 0x0000000000428049 in QtPrivate::FunctionPointer<void (CalendarResource::*)(KGAPI2::Job*)>::call<QtPrivate::List<KGAPI2::Job*>, void> (f=(void (CalendarResource::*)(CalendarResource * const, KGAPI2::Job *)) 0x4171f8 <CalendarResource::slotItemsRetrieved(KGAPI2::Job*)>, o=0x985ed0, arg=0x7ffee00e1130) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobjectdefs_impl.h:520
#16 0x0000000000423ef5 in QtPrivate::QSlotObject<void (CalendarResource::*)(KGAPI2::Job*), QtPrivate::List<KGAPI2::Job*>, void>::impl (which=1, this_=0x9b1330, r=0x985ed0, a=0x7ffee00e1130, ret=0x0) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qobject_impl.h:143
#17 0x00007f70ddacae1f in QtPrivate::QSlotObjectBase::call (a=0x7ffee00e1130, r=0x985ed0, this=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qobject_impl.h:124
#18 QMetaObject::activate (sender=0xaacd10, signalOffset=<optimized out>, local_signal_index=<optimized out>, argv=<optimized out>) at kernel/qobject.cpp:3698
#19 0x00007f70dffda2a0 in KGAPI2::Job::restart (this=0x401) at /var/btrfs/@src/libkgapi/src/core/job.cpp:373
#20 0x00007f70dffd7317 in KGAPI2::DeleteJob::handleReply (this=0x7f70dffd7317 <KGAPI2::DeleteJob::handleReply(QNetworkReply const*, QByteArray const&)+3>, reply=0x7ffee00e1170, rawData=...) at /var/btrfs/@src/libkgapi/src/core/deletejob.cpp:65
#21 0x0000000000ac41c0 in ?? ()
#22 0x00007ffee00e11d0 in ?? ()
#23 0x00007f70dffd9ec3 in KGAPI2::Job::setErrorString (this=0x47e4d2467cb12500, errorString=...) at /var/btrfs/@src/libkgapi/src/core/job.cpp:318
#24 0x00007f70dda9c282 in QCoreApplicationPrivate::sendThroughApplicationEventFilters (this=0x7ffee00e1200, receiver=0x908ff0, event=0x401) at kernel/qcoreapplication.cpp:1053
#25 0x00007f70de83605c in QApplicationPrivate::notify_helper (this=0x401, this@entry=0x908ff0, receiver=0xaacd10, receiver@entry=0xa8cd10, e=0x908ff0, e@entry=0xa8cd10) at kernel/qapplication.cpp:3716
#26 0x00007f70de83b516 in QApplication::notify (this=0x7ffee00e17c0, receiver=0xa8cd10, e=0xa8cd10) at kernel/qapplication.cpp:3499
#27 0x00007f70dda9c5bb in QCoreApplication::notifyInternal (this=0x7ffee00e17c0, receiver=0xaacd10, event=event@entry=0xa8cd10) at kernel/qcoreapplication.cpp:965
#28 0x00007f70dda9e9b6 in QCoreApplication::sendEvent (event=0xa8cd10, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:224
#29 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x904ad0) at kernel/qcoreapplication.cpp:1593
#30 0x00007f70dda9ee98 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1451
#31 0x00007f70ddaf2643 in postEventSourceDispatch (s=0x944ce0) at kernel/qeventdispatcher_glib.cpp:271
#32 0x00007f70d41c2137 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#33 0x00007f70d41c2390 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#34 0x00007f70d41c243c in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#35 0x00007f70ddaf2a4f in QEventDispatcherGlib::processEvents (this=0x93f4d0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#36 0x00007f70dda99d7a in QEventLoop::exec (this=this@entry=0x7ffee00e1700, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#37 0x00007f70ddaa1e1c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#38 0x00007f70e0ecd4ea in Akonadi::ResourceBase::init (r=0x985ed0) at /media/karry/data/src/akonadi/src/agentbase/resourcebase.cpp:605
#39 0x000000000041f826 in Akonadi::ResourceBase::init<CalendarResource> (argc=3, argv=0x7ffee00e18f8) at /usr/include/KF5/AkonadiAgentBase/resourcebase.h:196
#40 0x000000000041ab82 in main (argc=3, argv=0x7ffee00e18f8) at /media/karry/data/src/kdepim-runtime/resources/google/calendar/calendarresource.cpp:824


Reproducible: Couldn't Reproduce