Using recent-ish git (8aeb887da37b523eb40e28aadd8895e9009d4b6e), I got this crash shortly after opening a session: Program terminated with signal SIGSEGV, Segmentation fault. #0 0x00007fa09c12052a in KDevelop::TypeSystem::create (this=0x7fa09d2ee5a0 <KDevelop::TypeSystem::self()::system>, data=0x7fa0484410ca) at /home/flh/projects/kdevplatform/language/duchain/types/typeregister.cpp:27 27 return m_factories.value(data->typeClassId)->create(data); [Current thread is 1 (Thread 0x7fa052917700 (LWP 1091))] (gdb) bt full #0 0x00007fa09c12052a in KDevelop::TypeSystem::create(KDevelop::AbstractTypeData*) const (this=0x7fa09d2ee5a0 <KDevelop::TypeSystem::self()::system>, data=0x7fa0484410ca) at /home/flh/projects/kdevplatform/language/duchain/types/typeregister.cpp:27 #1 0x00007fa09c121ca1 in KDevelop::TypeRepository::typeForIndex(unsigned int) (index=408138) at /home/flh/projects/kdevplatform/language/duchain/types/typerepository.cpp:127 #2 0x00007fa09c132d99 in KDevelop::IndexedType::abstractType() const (this=0x7fa050867561) at /home/flh/projects/kdevplatform/language/duchain/types/indexedtype.cpp:65 #3 0x00007fa09c08d5bb in KDevelop::Declaration::abstractType() const (this=0x7fa04c5394a0) at /home/flh/projects/kdevplatform/language/duchain/declaration.cpp:261 #4 0x00007fa09c0c3c10 in KDevelop::FunctionDeclaration::additionalIdentity() const (this=0x7fa04c5394a0) at /home/flh/projects/kdevplatform/language/duchain/functiondeclaration.cpp:87 #5 0x00007fa09c0d8da5 in KDevelop::DeclarationId::getDeclaration(KDevelop::TopDUContext const*, bool) const (this=0x2001798, top=0x1f91ce0, instantiateIfRequired=true) at /home/flh/projects/kdevplatform/language/duchain/declarationid.cpp:172 decl = 0x7fa04c5394a0 filter = {<KDevelop::ConvenientEmbeddedSetIterator<KDevelop::IndexedDeclaration, KDevelop::IndexedDeclarationHandler>> = {<KDevelop::ConstantConvenientEmbeddedSet<KDevelop::IndexedDeclaration, KDevelop::IndexedDeclarationHandler>> = {m_data = 0x7fa054a46180, m_dataSize = 147, m_centralFreeItem = -1}, m_pos = 0}, boundStack = {<QVarLengthArray<QPair<QPair<unsigned int, unsigned int>, Utils::VirtualSetNode<KDevelop::IndexedTopDUContext, KDevelop::IndexedTopDUContextIndexConversion, KDevelop::RecursiveImportCacheRepository> >, 256>> = {a = 256, s = 4, ptr = 0x7fa052914b38, {array = "\207\000\000\000\223\000\000\000\302ۂ\003\000\000\000\000u\000\000\000\207\000\000\000\344\367\202\003\000\000\000\000\061\000\000\000u\000\000\000\032\f\203\003\000\000\000\000\005\000\000\000\060\000\000\000\304\026\203\003\000\000\000\000\003\000\000\000\005\000\000\000|\036\203\003\000\000\000\000f\000\000\000g\000\000\000\362\001\203\003\000\000\000\000`\000\000\000a\000\000\000\222\003\203\003\000\000\000\000\071\000\000\000:\000\000\000\374\n\203\003\000\000\000\000\065\000\000\000\066\000\000\000J\v\203\003\000\000\000\000\360K\221R\240\177\000\000\000L\221R\240\177\000\000\212\365\031\234\240\177\000\000\000L\221R\240\177\000\000\060L\221R\240\177\000\000@\340\016\235\240\177\000\000\060L\221R\240\177\000\000@"..., q_for_alignment_1 = 631360192647, q_for_alignment_2 = 3.1193338133859389e-312}}, <No data fields>}, m_rhs = {<KDevelop::IndexedTopDUContextIndexConversion> = {<No data fields>}, m_setIndex = 98714}, m_match = 4, m_matchBound = 4, m_matchingTo = {m_index = 281}, m_noFiltering = false} id = {m_index = 226400, {dd = 0x7fa0484f4cd0, cd = 0x7fa0484f4cd0}} ret = 0x0 #6 0x00007fa09c06fd4c in KDevelop::TopDUContext::usedDeclarationForIndex(unsigned int) const (this=0x1f91ce0, declarationIndex=4) at /home/flh/projects/kdevplatform/language/duchain/topducontext.cpp:1092 #7 0x00007fa09c1ae55e in KDevelop::CodeHighlightingInstance::highlightDUChain(KDevelop::DUContext*, QHash<KDevelop::Declaration*, unsigned int>, QVector<KDevelop::Declaration*>) (this=0x7fa040003730, context=0x1f93ea0, colorsForDeclarations=..., declarationsForColors=...) at /home/flh/projects/kdevplatform/language/highlighting/codehighlighting.cpp:297 decl = 0x7fa0547e6370 color = {cspec = QColor::Invalid, ct = {argb = {alpha = 65535, red = 0, green = 0, blue = 0, pad = 0}, ahsv = {alpha = 65535, hue = 0, saturation = 0, value = 0, pad = 0}, acmyk = {alpha = 65535, cyan = 0, magenta = 0, yellow = 0, black = 0}, ahsl = {alpha = 65535, hue = 0, saturation = 0, lightness = 0, pad = 0}, array = {65535, 0, 0, 0, 0}}} a = 112 lock = {m_lock = 0x7fa09c8f01e0 <KDevelop::(anonymous namespace)::Q_QGS_sdDUChainPrivate::innerFunction()::holder+32>, m_locked = true, m_timeout = 0} top = 0x1f91ce0 takeFreeColors = {<QListSpecialMethods<KDevelop::Declaration*>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fa09eefb2e0 <QListData::shared_null>}, d = 0x7fa09eefb2e0 <QListData::shared_null>}} children = {d = 0x28} #8 0x00007fa09c1ae7c7 in KDevelop::CodeHighlightingInstance::highlightDUChain(KDevelop::DUContext*, QHash<KDevelop::Declaration*, unsigned int>, QVector<KDevelop::Declaration*>) (this=0x7fa040003730, context=0x1f93de0, colorsForDeclarations=..., declarationsForColors=...) at /home/flh/projects/kdevplatform/language/highlighting/codehighlighting.cpp:314 child = 0x1f93ea0 _container_ = {c = {d = 0x1f93e70}, i = {i = 0x1f93e88}, e = {i = 0x1f93e90}, control = 1} lock = {m_lock = 0x7fa09c8f01e0 <KDevelop::(anonymous namespace)::Q_QGS_sdDUChainPrivate::innerFunction()::holder+32>, m_locked = false, m_timeout = 0} top = 0x1f91ce0 takeFreeColors = {<QListSpecialMethods<KDevelop::Declaration*>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fa09eefb2e0 <QListData::shared_null>}, d = 0x7fa09eefb2e0 <QListData::shared_null>}} children = {d = 0x1f93e70} #9 0x00007fa09c1ae7c7 in KDevelop::CodeHighlightingInstance::highlightDUChain(KDevelop::DUContext*, QHash<KDevelop::Declaration*, unsigned int>, QVector<KDevelop::Declaration*>) (this=0x7fa040003730, context=0x1f93d40, colorsForDeclarations=..., declarationsForColors=...) at /home/flh/projects/kdevplatform/language/highlighting/codehighlighting.cpp:314 child = 0x1f93de0 _container_ = {c = {d = 0x1f93db0}, i = {i = 0x1f93dc8}, e = {i = 0x1f93dd0}, control = 1} lock = {m_lock = 0x7fa09c8f01e0 <KDevelop::(anonymous namespace)::Q_QGS_sdDUChainPrivate::innerFunction()::holder+32>, m_locked = false, m_timeout = 0} top = 0x1f91ce0 takeFreeColors = {<QListSpecialMethods<KDevelop::Declaration*>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fa09eefb2e0 <QListData::shared_null>}, d = 0x7fa09eefb2e0 <QListData::shared_null>}} children = {d = 0x1f93db0} #10 0x00007fa09c1ae7c7 in KDevelop::CodeHighlightingInstance::highlightDUChain(KDevelop::DUContext*, QHash<KDevelop::Declaration*, unsigned int>, QVector<KDevelop::Declaration*>) (this=0x7fa040003730, context=0x1f91ce0, colorsForDeclarations=..., declarationsForColors=...) at /home/flh/projects/kdevplatform/language/highlighting/codehighlighting.cpp:314 child = 0x1f93d40 ---Type <return> to continue, or q <return> to quit--- _container_ = {c = {d = 0x200d340}, i = {i = 0x200d458}, e = {i = 0x200d528}, control = 1} lock = {m_lock = 0x7fa09c8f01e0 <KDevelop::(anonymous namespace)::Q_QGS_sdDUChainPrivate::innerFunction()::holder+32>, m_locked = false, m_timeout = 0} top = 0x1f91ce0 takeFreeColors = {<QListSpecialMethods<KDevelop::Declaration*>> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fa09eefb2e0 <QListData::shared_null>}, d = 0x7fa09eefb2e0 <QListData::shared_null>}} children = {d = 0x200d340} #11 0x00007fa09c1adb52 in KDevelop::CodeHighlightingInstance::highlightDUChain(KDevelop::TopDUContext*) (this=0x7fa040003730, context=0x1f91ce0) at /home/flh/projects/kdevplatform/language/highlighting/codehighlighting.cpp:212 #12 0x00007fa09c1ad823 in KDevelop::CodeHighlighting::highlightDUChain(KDevelop::ReferencedTopDUContext) (this=0x1a75230, context=...) at /home/flh/projects/kdevplatform/language/highlighting/codehighlighting.cpp:193 url = {m_index = 365400} urlLock = {m_url = {m_index = 365400}} lock = {m_lock = 0x7fa09c8f01e0 <KDevelop::(anonymous namespace)::Q_QGS_sdDUChainPrivate::innerFunction()::holder+32>, m_locked = false, m_timeout = 0} revision = 0 __PRETTY_FUNCTION__ = "virtual void KDevelop::CodeHighlighting::highlightDUChain(KDevelop::ReferencedTopDUContext)" instance = 0x7fa040003730 highlighting = 0x43bfe38 #13 0x00007fa09bffe8b7 in KDevelop::ParseJob::highlightDUChain() (this=0x4f78590) at /home/flh/projects/kdevplatform/language/backgroundparser/parsejob.cpp:501 #14 0x00007fa09bffe5fe in KDevelop::ParseJob::isUpdateRequired(KDevelop::IndexedString const&) (this=0x4f78590, languageString=...) at /home/flh/projects/kdevplatform/language/backgroundparser/parsejob.cpp:477 file = @0x7fa040003370: {d = 0x1f9c3f0} _container_ = {c = {<QListSpecialMethods<QExplicitlySharedDataPointer<KDevelop::ParsingEnvironmentFile> >> = {<No data fields>}, {p = {static shared_null = {ref = {atomic = {_q_value = {<std::__atomic_base<int>> = {static _S_alignment = 4, _M_i = -1}, <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}}, d = 0x7fa040003360}, d = 0x7fa040003360}}, i = {i = 0x7fa040003370}, e = {i = 0x7fa040003378}, control = 1} lock = {m_lock = 0x7fa09c8f01e0 <KDevelop::(anonymous namespace)::Q_QGS_sdDUChainPrivate::innerFunction()::holder+32>, m_locked = false, m_timeout = 0} __PRETTY_FUNCTION__ = "bool KDevelop::ParseJob::isUpdateRequired(const KDevelop::IndexedString&)" #15 0x00007fa065e888e1 in ClangParseJob::run(QSharedPointer<ThreadWeaver::JobInterface>, ThreadWeaver::Thread*) () at /usr/local/lib64/plugins/kdevplatform/26/kdevclangsupport.so #16 0x00007fa09b371586 in ThreadWeaver::IdDecorator::run(QSharedPointer<ThreadWeaver::JobInterface>, ThreadWeaver::Thread*) () at /usr/lib/libKF5ThreadWeaver.so.5 #17 0x00007fa09b371b88 in ThreadWeaver::Executor::run(QSharedPointer<ThreadWeaver::JobInterface> const&, ThreadWeaver::Thread*) () at /usr/lib/libKF5ThreadWeaver.so.5 #18 0x00007fa09b370a9a in ThreadWeaver::Job::execute(QSharedPointer<ThreadWeaver::JobInterface> const&, ThreadWeaver::Thread*) () at /usr/lib/libKF5ThreadWeaver.so.5 #19 0x00007fa09b370140 in ThreadWeaver::Thread::run() () at /usr/lib/libKF5ThreadWeaver.so.5 #20 0x00007fa09ec73d78 in () at /usr/lib/libQt5Core.so.5 #21 0x00007fa09538e454 in start_thread () at /usr/lib/libpthread.so.0 #22 0x00007fa09e06e7df in clone () at /usr/lib/libc.so.6
This looks rather like a corrupted duchain cache, version mismatch etc., and I don't remember seeing anything similar more recently. Closing.