KDevelop sometimes crashes when I try to build project. This is not reproducible, it happens from time to time, usually after some time when KDevelop is not used. 

Using up-to-date git master for both kdevplatform and kdevelop

Backtrace:
Thread 1 (Thread 0x7f9c9f389880 (LWP 28191)):
[KCrash Handler]
#6  QList (l=<error reading variable: Cannot access memory at address 0x20>, this=0x7fffb5aa67b0) at /usr/include/QtCore/qlist.h:122
#7  QStringList (l=<error reading variable: Cannot access memory at address 0x20>, this=0x7fffb5aa67b0) at /usr/include/QtCore/qstringlist.h:71
#8  KDevelop::IPlugin::extensions (this=0x0) at /home/radek/kde/kdevplatform/interfaces/iplugin.cpp:155
#9  0x00007f9c751c717e in KDevelop::IPlugin::extension<KDevelop::IProjectBuilder> (this=this@entry=0x0) at /home/radek/kdevelop/include/kdevplatform/interfaces/iplugin.h:183
#10 0x00007f9c751b9654 in CMakeManager::builder (this=<optimized out>) at /home/radek/kde/kdevelop/projectmanagers/cmake/cmakemanager.cpp:993
#11 0x00007f9cad6ac4c7 in KDevelop::BuilderJobPrivate::addJob (this=0x71fc3d0, t=<optimized out>, item=0x142b8e0) at /home/radek/kde/kdevplatform/project/builderjob.cpp:70
#12 0x00007f9c8cdc2041 in BuildItemBuilderJob::BuildItemBuilderJob (this=0x5225550, t=KDevelop::BuilderJob::Build, items=...) at /home/radek/kde/kdevplatform/plugins/projectmanagerview/builditembuilderjob.cpp:35
#13 0x00007f9c8cdb5651 in ProjectManagerViewPlugin::runBuilderJob (this=<optimized out>, t=KDevelop::BuilderJob::Build) at /home/radek/kde/kdevplatform/plugins/projectmanagerview/projectmanagerviewplugin.cpp:344
#14 0x00007f9cb0f49b9f in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib64/libQtCore.so.4
#15 0x00007f9cb00c41c2 in QAction::triggered (this=this@entry=0x325a600, _t1=false) at .moc/release-shared/moc_qaction.cpp:276
#16 0x00007f9cb00c43b0 in QAction::activate (this=0x325a600, event=event@entry=QAction::Trigger) at kernel/qaction.cpp:1257
#17 0x00007f9cb00c4517 in QAction::event (this=<optimized out>, e=<optimized out>) at kernel/qaction.cpp:1183
#18 0x00007f9cb1672417 in KAction::event (this=<optimized out>, event=0x7fffb5aa7050) at /usr/src/debug/kdelibs-4.8.90/kdeui/actions/kaction.cpp:131
#19 0x00007f9cb00ca37c in QApplicationPrivate::notify_helper (this=this@entry=0x13d7d70, receiver=receiver@entry=0x325a600, e=e@entry=0x7fffb5aa7050) at kernel/qapplication.cpp:4551
#20 0x00007f9cb00ce7fa in QApplication::notify (this=0x7fffb5aa8960, receiver=0x325a600, e=0x7fffb5aa7050) at kernel/qapplication.cpp:4412
#21 0x00007f9cb174b756 in KApplication::notify (this=0x7fffb5aa8960, receiver=0x325a600, event=0x7fffb5aa7050) at /usr/src/debug/kdelibs-4.8.90/kdeui/kernel/kapplication.cpp:311
#22 0x00007f9cb0f333ee in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQtCore.so.4
#23 0x00007f9cb00fb0f4 in sendEvent (event=0x7fffb5aa7050, receiver=<optimized out>) at ../../src/corelib/kernel/qcoreapplication.h:231
#24 QShortcutMap::dispatchEvent (this=this@entry=0x13d7e90, e=e@entry=0x7fffb5aa7620) at kernel/qshortcutmap.cpp:879
#25 0x00007f9cb00fc603 in QShortcutMap::tryShortcutEvent (this=0x13d7e90, o=<optimized out>, e=0x7fffb5aa7620) at kernel/qshortcutmap.cpp:364
#26 0x00007f9cb00d04d9 in QApplication::notify (this=0x7fffb5aa8960, receiver=0x5189120, e=0x7fffb5aa7620) at kernel/qapplication.cpp:3975
#27 0x00007f9cb174b756 in KApplication::notify (this=0x7fffb5aa8960, receiver=0x5189120, event=0x7fffb5aa7620) at /usr/src/debug/kdelibs-4.8.90/kdeui/kernel/kapplication.cpp:311
#28 0x00007f9cb0f333ee in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQtCore.so.4
#29 0x00007f9cb016654a in QKeyMapper::sendKeyEvent (keyWidget=keyWidget@entry=0x5189120, grab=grab@entry=false, type=QEvent::KeyPress, code=16777271, modifiers=..., text=..., autorepeat=autorepeat@entry=false, count=1, nativeScanCode=74, nativeVirtualKey=65477, nativeModifiers=16) at kernel/qkeymapper_x11.cpp:1866
#30 0x00007f9cb0166981 in QKeyMapperPrivate::translateKeyEvent (this=0x1420e20, keyWidget=0x5189120, event=0x7fffb5aa8040, grab=false) at kernel/qkeymapper_x11.cpp:1836
#31 0x00007f9cb01443f8 in QApplication::x11ProcessEvent (this=0x7fffb5aa8960, event=0x7fffb5aa8040) at kernel/qapplication_x11.cpp:3539
#32 0x00007f9cb016a60c in x11EventSourceDispatch (s=0x13d9100, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:148
#33 0x00007f9ca83f16e5 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#34 0x00007f9ca83f1a18 in ?? () from /lib64/libglib-2.0.so.0
#35 0x00007f9ca83f1ad4 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#36 0x00007f9cb0f614e6 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#37 0x00007f9cb016a2ee in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:207
#38 0x00007f9cb0f3213f in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#39 0x00007f9cb0f323c8 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#40 0x00007f9cb0f371b8 in QCoreApplication::exec() () from /lib64/libQtCore.so.4
#41 0x000000000040e312 in main (argc=<optimized out>, argv=<optimized out>) at /home/radek/kde/kdevelop/app/main.cpp:518

(+ ~10 other threads without interesting info)

Reproducible: Sometimes

Steps to Reproduce:
1. Just try to build current project (hit F8). I can't figure out any more specific details.

Actual Results:  
KDevelop crashes.