Opened project "kdelibs", which took quite some time. I opened the toplevel CMakeLists.txt, while the import was not yet finished -> deadlock:
(gdb) bt
#0  0x00007ffddc6d63bd in nanosleep () at ../sysdeps/unix/syscall-template.S:82
#1  0x00007ffddc700984 in usleep (useconds=<optimized out>) at ../sysdeps/unix/sysv/linux/usleep.c:33
#2  0x00007ffddaad0c3c in KDevelop::DUChainLock::lockForWrite (this=0x3610968, timeout=0) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/language/duchain/duchainlock.cpp:190
#3  0x00007ffddaad0e01 in KDevelop::DUChainWriteLocker::lock (this=0x7fff5ec8bb70) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/language/duchain/duchainlock.cpp:284
#4  0x00007ffddaa7ff32 in KDevelop::DUChain::documentLoadedPrepare (this=0x3633c30, doc=0x729a8c0) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/language/duchain/duchain.cpp:1517
#5  0x00007ffddaa80854 in qt_static_metacall (_a=0x7fff5ec8bf70, _id=<optimized out>, _o=0x3633c30, _c=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/language/duchain.moc:143
#6  KDevelop::DUChain::qt_static_metacall (_o=0x3633c30, _c=<optimized out>, _id=<optimized out>, _a=0x7fff5ec8bf70) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/language/duchain.moc:133
#7  0x00007ffdddb2a659 in QMetaObject::activate (sender=0x272e8a0, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fff5ec8bf70) at kernel/qobject.cpp:3539
#8  0x00007ffddedfc742 in KDevelop::IDocumentController::documentLoadedPrepare (this=<optimized out>, _t1=0x729a8c0) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/interfaces/idocumentcontroller.moc:326
#9  0x00007ffddedfa1e0 in KDevelop::IDocument::notifyLoaded (this=0x729a8c0) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/interfaces/idocument.cpp:130
#10 0x00007ffdded5027f in slotDocumentLoaded (this=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/textdocument.cpp:207
#11 qt_static_metacall (_a=<optimized out>, _id=<optimized out>, _o=<optimized out>, _c=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/shell/textdocument.moc:73
#12 KDevelop::TextDocument::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/shell/textdocument.moc:61
#13 0x00007ffdddb2a659 in QMetaObject::activate (sender=0x7284b90, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fff5ec8c420) at kernel/qobject.cpp:3539
#14 0x00007ffddec92722 in KTextEditor::Document::textChanged (this=<optimized out>, _t1=0x7284b90) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97_build/interfaces/ktexteditor/document.moc:194
#15 0x00007ffdc3e36f7e in KateDocument::openFile (this=0x7284b90) at /var/tmp/paludis/kde-base-katepart-4.9.97/work/katepart-4.9.97/part/document/katedocument.cpp:1983
#16 0x00007ffddb2db6bc in KParts::ReadOnlyPartPrivate::openLocalFile (this=0x729a7e0) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97/kparts/part.cpp:591
#17 0x00007ffddb2dbc74 in KParts::ReadOnlyPart::openUrl (this=0x7284b90, url=...) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97/kparts/part.cpp:555
#18 0x00007ffdded4f5df in KDevelop::TextDocument::createViewWidget (this=0x729a8a0, parent=0x729ae80) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/textdocument.cpp:361
#19 0x00007ffdded4e038 in initialize (this=0x729ae80) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/textdocument.cpp:774
#20 KDevelop::TextEditorWidget::initialize (this=0x729ae80) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/textdocument.cpp:769
#21 0x00007ffdded4eaa9 in KDevelop::TextEditorWidget::TextEditorWidget (this=0x729ae80, view=0x7299df0, parent=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/textdocument.cpp:761
#22 0x00007ffdded4eaf4 in KDevelop::TextView::createWidget (this=0x7299df0, parent=0x35f9400) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/textdocument.cpp:651
#23 0x00007ffdde361dd6 in Sublime::View::widget (this=0x7299df0, parent=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/sublime/view.cpp:82
#24 0x00007ffdde35ceb1 in Sublime::MainWindowPrivate::ViewCreator::operator() (this=0x7fff5ec8cfe0, index=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/sublime/mainwindow_p.cpp:322
#25 0x00007ffdde3612e8 in Sublime::Area::walkViewsInternal<Sublime::MainWindowPrivate::ViewCreator> (this=0x1d8d0d0, op=..., index=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/sublime/areawalkers.h:32
#26 0x00007ffdde35f8e7 in walkViews<Sublime::MainWindowPrivate::ViewCreator> (index=0x1d8bd60, op=..., this=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/sublime/areawalkers.h:48
#27 Sublime::MainWindowPrivate::viewAdded (this=0x2685720, index=0x1d8bd60, view=0x7299df0) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/sublime/mainwindow_p.cpp:503
#28 0x00007ffdddb2a659 in QMetaObject::activate (sender=0x1d8d0d0, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fff5ec8d1c0) at kernel/qobject.cpp:3539
#29 0x00007ffdde34969c in Sublime::Area::viewAdded (this=<optimized out>, _t1=0x1d8bd60, _t2=0x7299df0) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/sublime/area.moc:129
#30 0x00007ffdde3497ac in Sublime::Area::addView (this=0x1d8d0d0, view=0x7299df0, index=0x1d8bd60, after=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/sublime/area.cpp:173
#31 0x00007ffdded5a1eb in KDevelop::DocumentControllerPrivate::openDocumentInternal (this=0x2732760, doc=0x729a8c0, range=..., activationParams=..., buddy=0x1d8bd60)
    at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/documentcontroller.cpp:478
---Type <return> to continue, or q <return> to quit---
#32 0x00007ffdded5ada4 in KDevelop::DocumentControllerPrivate::openDocumentInternal (this=0x2732760, inputUrl=..., prefName=..., range=[ (-1, -1) -> (-1, -1) ], encoding=..., activationParams=..., buddy=0x0)
    at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/documentcontroller.cpp:319
#33 0x00007ffdded54857 in KDevelop::DocumentController::openDocument (this=0x272e8a0, inputUrl=..., range=[ (-1, -1) -> (-1, -1) ], activationParams=..., encoding=..., buddy=warning: (Internal error: pc 0x0 in read in psymtab, but not in symtab.)

0x0)
    at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/shell/documentcontroller.cpp:700
#34 0x00007ffdccbb4767 in OpenWithPlugin::openDefault (this=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/plugins/openwith/openwithplugin.cpp:197
#35 0x00007ffdccbb48fb in OpenWithPlugin::openFilesInternal (this=0x3f6f4d0, files=...) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/plugins/openwith/openwithplugin.cpp:243
#36 0x00007ffdc8030de1 in openFiles (files=...) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/plugins/filemanager/../openwith/iopenwith.h:51
#37 FileManager::openFile (this=<optimized out>, file=...) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999/plugins/filemanager/filemanager.cpp:113
#38 0x00007ffdc80310e9 in qt_static_metacall (_a=<optimized out>, _id=<optimized out>, _o=0x58c80d0, _c=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/plugins/filemanager/filemanager.moc:58
#39 FileManager::qt_static_metacall (_o=0x58c80d0, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at /var/tmp/paludis/dev-util-kdevplatform-9999/work/kdevplatform-9999_build/plugins/filemanager/filemanager.moc:52
#40 0x00007ffdddb2a659 in QMetaObject::activate (sender=0x59169a0, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fff5ec8de00) at kernel/qobject.cpp:3539
#41 0x00007ffddad67515 in KDirOperator::fileSelected (this=<optimized out>, _t1=...) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97_build/kfile/kdiroperator.moc:335
#42 0x00007ffddad675f5 in KDirOperator::Private::_k_slotActivated (this=0x593d290, index=...) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97/kfile/kdiroperator.cpp:2364
#43 0x00007ffddad6ccee in qt_static_metacall (_a=<optimized out>, _id=<optimized out>, _o=<optimized out>, _c=<optimized out>) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97_build/kfile/kdiroperator.moc:227
#44 KDirOperator::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97_build/kfile/kdiroperator.moc:160
#45 0x00007ffdddb2a659 in QMetaObject::activate (sender=0x593f520, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fff5ec8dfe0) at kernel/qobject.cpp:3539
#46 0x00007ffddd3c94a5 in QAbstractItemView::activated (this=<optimized out>, _t1=...) at .moc/release-shared/moc_qabstractitemview.cpp:362
#47 0x00007ffddd3c999f in QAbstractItemView::mouseReleaseEvent (this=0x593f520, event=0x7fff5ec8ef70) at itemviews/qabstractitemview.cpp:1821
#48 0x00007ffddcef8cc2 in QWidget::event (this=0x593f520, event=0x7fff5ec8ef70) at kernel/qwidget.cpp:8375
#49 0x00007ffddd2b5006 in QFrame::event (this=0x593f520, e=0x7fff5ec8ef70) at widgets/qframe.cpp:557
#50 0x00007ffddd3c832b in QAbstractItemView::viewportEvent (this=0x593f520, event=0x7fff5ec8ef70) at itemviews/qabstractitemview.cpp:1644
#51 0x00007ffddd410195 in QTreeView::viewportEvent (this=0x593f520, event=0x7fff5ec8ef70) at itemviews/qtreeview.cpp:1257
#52 0x00007ffdddb16d66 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<optimized out>, receiver=0x593cb50, event=0x7fff5ec8ef70) at kernel/qcoreapplication.cpp:1056
#53 0x00007ffddcea622f in notify_helper (e=0x7fff5ec8ef70, receiver=0x593cb50, this=0x1e066f0) at kernel/qapplication.cpp:4558
#54 QApplicationPrivate::notify_helper (this=0x1e066f0, receiver=0x593cb50, e=0x7fff5ec8ef70) at kernel/qapplication.cpp:4534
#55 0x00007ffddceac339 in QApplication::notify (this=<optimized out>, receiver=0x593cb50, e=0x7fff5ec8ef70) at kernel/qapplication.cpp:4105
#56 0x00007ffdde0e0c76 in KApplication::notify (this=0x7fff5ec8fd70, receiver=0x593cb50, event=0x7fff5ec8ef70) at /var/tmp/paludis/kde-base-kdelibs-4.9.97/work/kdelibs-4.9.97/kdeui/kernel/kapplication.cpp:311
#57 0x00007ffdddb16bec in QCoreApplication::notifyInternal (this=0x7fff5ec8fd70, receiver=0x593cb50, event=0x7fff5ec8ef70) at kernel/qcoreapplication.cpp:946
#58 0x00007ffddcea7222 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#59 QApplicationPrivate::sendMouseEvent (receiver=0x593cb50, event=0x7fff5ec8ef70, alienWidget=0x593cb50, nativeWidget=0x59bf400, buttonDown=0x593cb50, lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:3173
#60 0x00007ffddcf21eb8 in QETWidget::translateMouseEvent (this=0x59bf400, event=<optimized out>) at kernel/qapplication_x11.cpp:4516
#61 0x00007ffddcf20cca in QApplication::x11ProcessEvent (this=0x7fff5ec8fd70, event=0x7fff5ec8f690) at kernel/qapplication_x11.cpp:3639
#62 0x00007ffddcf4823a in x11EventSourceDispatch (s=0x1e09010, callback=warning: (Internal error: pc 0x0 in read in psymtab, but not in symtab.)

0x0, user_data=warning: (Internal error: pc 0x0 in read in psymtab, but not in symtab.)

0x0) at kernel/qguieventdispatcher_glib.cpp:146
---Type <return> to continue, or q <return> to quit---
#63 0x00007ffdd80603b3 in g_main_dispatch (context=0x1e07d00) at gmain.c:2715
#64 g_main_context_dispatch (context=0x1e07d00) at gmain.c:3219
#65 0x00007ffdd8060700 in g_main_context_iterate (dispatch=1, block=<optimized out>, context=0x1e07d00, self=<optimized out>) at gmain.c:3290
#66 g_main_context_iterate (context=0x1e07d00, block=<optimized out>, dispatch=1, self=<optimized out>) at gmain.c:3227
#67 0x00007ffdd80607c4 in g_main_context_iteration (context=0x1e07d00, may_block=1) at gmain.c:3351
#68 0x00007ffdddb4528f in QEventDispatcherGlib::processEvents (this=0x1d48e80, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#69 0x00007ffddcf47ede in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#70 0x00007ffdddb15752 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#71 0x00007ffdddb159a7 in QEventLoop::exec (this=0x7fff5ec8fa20, flags=...) at kernel/qeventloop.cpp:204
#72 0x00007ffdddb1a695 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1218
#73 0x0000000000410726 in main (argc=<optimized out>, argv=<optimized out>) at /var/tmp/paludis/dev-util-kdevelop-9999/work/kdevelop-9999/app/main.cpp:506

kdevplatform last commit:
474b60dba8bc889af4c2b40ffe91d6967fefb6d8
kdevelop last commit:
976672fc2e7386f622c86b480106cde55eff0519

Reproducible: Always