E.g. this is what happens when I type «b In». I cannot reproduce it with stock LLDB. (lldb) b In0 lldb 0x0000000102638705 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37 1 lldb 0x0000000102637d77 llvm::sys::RunSignalHandlers() + 39 2 lldb 0x0000000102638d58 SignalHandler(int) + 264 3 libsystem_platform.dylib 0x00007fff6ca5642d _sigtramp + 29 4 libsystem_platform.dylib 000000000000000000 _sigtramp + 2472188912 5 LLDB 0x0000000102dbf200 llvm::BinaryStreamReader::BinaryStreamReader(llvm::BinaryStream&) + 32 6 LLDB 0x00000001030ba527 llvm::pdb::ModuleDebugStreamRef::reload() + 39 7 LLDB 0x0000000102d589ff lldb_private::npdb::CompileUnitIndex::GetOrCreateCompiland(unsigned short) + 319 8 LLDB 0x0000000102d72077 lldb_private::npdb::SymbolFileNativePDB::ParseCompileUnitAtIndex(unsigned int) + 119 9 LLDB 0x00000001029cf71d lldb_private::SymbolVendor::GetCompileUnitAtIndex(unsigned long) + 221 10 LLDB 0x000000010288659a lldb_private::Module::GetCompileUnitAtIndex(unsigned long) + 106 11 LLDB 0x000000010289fb10 lldb_private::SearchFilter::DoCUIteration(std::__1::shared_ptr const&, lldb_private::SymbolContext const&, lldb_private::Searcher&) + 208 12 LLDB 0x000000010289f7b3 lldb_private::SearchFilter::DoModuleIteration(lldb_private::SymbolContext const&, lldb_private::Searcher&) + 419 13 LLDB 0x000000010289f5f4 lldb_private::SearchFilter::Search(lldb_private::Searcher&) + 180 14 LLDB 0x0000000102e5563d lldb_private::CommandCompletions::SourceFileCompleter::DoCompletion(lldb_private::SearchFilter*) + 29 15 LLDB 0x0000000102e54c28 lldb_private::CommandCompletions::SourceFiles(lldb_private::CommandInterpreter&, lldb_private::CompletionRequest&, lldb_private::SearchFilter*) + 200 16 LLDB 0x0000000102e555ed lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(lldb_private::CommandInterpreter&, unsigned int, lldb_private::CompletionRequest&, lldb_private::SearchFilter*) + 93 17 LLDB 0x000000010293b331 lldb_private::CommandObjectRegexCommand::HandleCompletion(lldb_private::CompletionRequest&) + 33 18 LLDB 0x00000001029310e8 lldb_private::CommandInterpreter::HandleCompletionMatches(lldb_private::CompletionRequest&) + 424 19 LLDB 0x000000010293135d lldb_private::CommandInterpreter::HandleCompletion(char const*, char const*, char const*, int, int, lldb_private::StringList&, lldb_private::StringList&) + 349 20 LLDB 0x0000000102871eaa lldb_private::IOHandlerDelegate::IOHandlerComplete(lldb_private::IOHandler&, char const*, char const*, char const*, int, int, lldb_private::StringList&, lldb_private::StringList&) + 90 21 LLDB 0x0000000102872547 lldb_private::IOHandlerEditline::AutoCompleteCallback(char const*, char const*, char const*, int, int, lldb_private::StringList&, lldb_private::StringList&, void*) + 55 22 LLDB 0x00000001029155fe lldb_private::Editline::TabCommand(int) + 110 23 LLDB 0x0000000102917931 lldb_private::Editline::ConfigureEditor(bool)::$_13::__invoke(editline*, int) + 33 24 libedit.3.dylib 0x00007fff6a3fc7db el_wgets + 484 25 libedit.3.dylib 0x00007fff6a4078bb el_gets + 37 26 LLDB 0x0000000102916df7 lldb_private::Editline::GetLine(std::__1::basic_string, std::__1::allocator >&, bool&) + 439 27 LLDB 0x00000001028727bc lldb_private::IOHandlerEditline::GetLine(std::__1::basic_string, std::__1::allocator >&, bool&) + 60 28 LLDB 0x0000000102872f3e lldb_private::IOHandlerEditline::Run() + 190 29 LLDB 0x000000010285a3cb lldb_private::Debugger::ExecuteIOHandlers() + 123 30 LLDB 0x000000010293589c lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool, lldb_private::CommandInterpreterRunOptions&) + 156 31 LLDB 0x00000001026deb91 lldb::SBDebugger::RunCommandInterpreter(bool, bool) + 209 32 lldb 0x0000000102623665 Driver::MainLoop() + 2853 33 lldb 0x00000001026245d2 main + 1634 34 libdyld.dylib 0x00007fff6c85d7fd start + 1 35 libdyld.dylib 0x000000000000000f start + 2474256403 Stack dump: 0. Program arguments: /Applications/Xcode.app/Contents/Developer/usr/bin/lldb -o settings set plugin.process.gdb-remote.target-definition-file Scripts/x86_64_target_definition.py -o gdb-remote 8864 -o target modules add -s GdbSyms/Bin/X64_CLANGPDB/GdbSyms.pdb GdbSyms/Bin/X64_CLANGPDB/GdbSyms.dll -o command script import Scripts/lldb_uefi.py -o command script add -c lldb_uefi.ReloadUefi reload-uefi -o reload-uefi -o b DebugBreak ./maclldb.tool: line 33: 37553 Segmentation fault: 11 "$LLDB" -o "settings set plugin.process.gdb-remote.target-definition-file Scripts/x86_64_target_definition.py" -o "gdb-remote $LLDB_PORT" -o "target modules add -s GdbSyms/Bin/X64_CLANGPDB/GdbSyms.pdb GdbSyms/Bin/X64_CLANGPDB/GdbSyms.dll" -o "command script import Scripts/lldb_uefi.py" -o "command script add -c lldb_uefi.ReloadUefi reload-uefi" -o "reload-uefi" -o "b DebugBreak" This I cannot reproduce with stock GDB either: (lldb) p mDebugInfoTableHeader 0 lldb 0x0000000102e13705 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37 1 lldb 0x0000000102e12d77 llvm::sys::RunSignalHandlers() + 39 2 lldb 0x0000000102e13d58 SignalHandler(int) + 264 3 libsystem_platform.dylib 0x00007fff6ca5642d _sigtramp + 29 4 libsystem_platform.dylib 0xaae108ecfd74df7c _sigtramp + 2429516652 5 LLDB 0x000000010359e200 llvm::BinaryStreamReader::BinaryStreamReader(llvm::BinaryStream&) + 32 6 LLDB 0x0000000103899527 llvm::pdb::ModuleDebugStreamRef::reload() + 39 7 LLDB 0x00000001035379ff lldb_private::npdb::CompileUnitIndex::GetOrCreateCompiland(unsigned short) + 319 8 LLDB 0x0000000103540a77 lldb_private::npdb::PdbAstBuilder::ParseAllNamespacesPlusChildrenOf(llvm::Optional) + 663 9 LLDB 0x00000001035414e2 lldb_private::npdb::PdbAstBuilder::ParseDeclsForContext(clang::DeclContext&) + 82 10 LLDB 0x0000000103550fef lldb_private::npdb::SymbolFileNativePDB::ParseDeclsForContext(lldb_private::CompilerDeclContext) + 63 11 LLDB 0x000000010315604c lldb_private::ClangASTContext::DeclContextFindDeclByName(void*, lldb_private::ConstString, bool) + 668 12 LLDB 0x00000001031627b9 lldb_private::CompilerDeclContext::FindDeclByName(lldb_private::ConstString, bool) + 57 13 LLDB 0x00000001032f1b76 lldb_private::ClangExpressionDeclMap::FindExternalVisibleDecls(lldb_private::NameSearchContext&, std::__1::shared_ptr, lldb_private::CompilerDeclContext&, unsigned int) + 1014 14 LLDB 0x00000001032f1334 lldb_private::ClangExpressionDeclMap::FindExternalVisibleDecls(lldb_private::NameSearchContext&) + 628 15 LLDB 0x00000001032e63b6 lldb_private::ClangASTSource::FindExternalVisibleDeclsByName(clang::DeclContext const*, clang::DeclarationName) + 1174 16 LLDB 0x000000010635e802 clang::DeclContext::lookup(clang::DeclarationName) const + 754 17 LLDB 0x0000000105ff1f66 LookupDirect(clang::Sema&, clang::LookupResult&, clang::DeclContext const*) + 86 18 LLDB 0x0000000105fee3e9 clang::Sema::CppLookupName(clang::LookupResult&, clang::Scope*) + 3257 19 LLDB 0x0000000105ff1795 clang::Sema::LookupName(clang::LookupResult&, clang::Scope*, bool) + 725 20 LLDB 0x0000000105d66a63 clang::Sema::ClassifyName(clang::Scope*, clang::CXXScopeSpec&, clang::IdentifierInfo*&, clang::SourceLocation, clang::Token const&, bool, std::__1::unique_ptr >) + 419 21 LLDB 0x0000000105b0ac14 clang::Parser::TryAnnotateName(bool, std::__1::unique_ptr >) + 484 22 LLDB 0x0000000105aeb55a clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector&, clang::Parser::AllowedConstructsKind, clang::SourceLocation*, clang::Parser::ParsedAttributesWithRange&) + 394 23 LLDB 0x0000000105aeb279 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector&, clang::Parser::AllowedConstructsKind, clang::SourceLocation*) + 201 24 LLDB 0x0000000105af263c clang::Parser::ParseCompoundStatementBody(bool) + 1644 25 LLDB 0x0000000105af3131 clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) + 161 26 LLDB 0x0000000105b09780 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) + 2608 27 LLDB 0x0000000105a84045 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) + 1781 28 LLDB 0x0000000105b08a37 clang::Parser::ParseDeclOrFunctionDefInternal(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) + 695 29 LLDB 0x0000000105b084e3 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) + 339 30 LLDB 0x0000000105b06c57 clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) + 2535 31 LLDB 0x0000000105b05d97 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr&) + 679 32 LLDB 0x0000000105a71855 clang::ParseAST(clang::Sema&, bool, bool) + 453 33 LLDB 0x0000000105a71672 clang::ParseAST(clang::Preprocessor&, clang::ASTConsumer*, clang::ASTContext&, bool, clang::TranslationUnitKind, clang::CodeCompleteConsumer*, bool) + 194 34 LLDB 0x00000001033094a1 lldb_private::ClangExpressionParser::ParseInternal(lldb_private::DiagnosticManager&, clang::CodeCompleteConsumer*, unsigned int, unsigned int) + 1729 35 LLDB 0x0000000103315793 lldb_private::ClangUserExpression::Parse(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, lldb_private::ExecutionPolicy, bool, bool) + 499 36 LLDB 0x00000001030deaf5 lldb_private::UserExpression::Evaluate(lldb_private::ExecutionContext&, lldb_private::EvaluateExpressionOptions const&, llvm::StringRef, llvm::StringRef, lldb_private::SharingPtr&, lldb_private::Status&, unsigned int, std::__1::basic_string, std::__1::allocator >*, std::__1::shared_ptr*) + 1701 37 LLDB 0x0000000103241542 lldb_private::Target::EvaluateExpression(llvm::StringRef, lldb_private::ExecutionContextScope*, lldb_private::SharingPtr&, lldb_private::EvaluateExpressionOptions const&, std::__1::basic_string, std::__1::allocator >*) + 418 38 LLDB 0x000000010364dd06 lldb_private::CommandObjectExpression::EvaluateExpression(llvm::StringRef, lldb_private::Stream*, lldb_private::Stream*, lldb_private::CommandReturnObject*) + 566 39 LLDB 0x000000010364ec56 lldb_private::CommandObjectExpression::DoExecute(llvm::StringRef, lldb_private::CommandReturnObject&) + 1270 40 LLDB 0x000000010311877b lldb_private::CommandObjectRaw::Execute(char const*, lldb_private::CommandReturnObject&) + 427 41 LLDB 0x000000010310fd25 lldb_private::CommandInterpreter::HandleCommand(char const*, lldb_private::LazyBool, lldb_private::CommandReturnObject&, lldb_private::ExecutionContext*, bool, bool) + 2805 42 LLDB 0x0000000103113d61 lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&, std::__1::basic_string, std::__1::allocator >&) + 657 43 LLDB 0x0000000103051f9d lldb_private::IOHandlerEditline::Run() + 285 44 LLDB 0x00000001030393cb lldb_private::Debugger::ExecuteIOHandlers() + 123 45 LLDB 0x000000010311489c lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool, lldb_private::CommandInterpreterRunOptions&) + 156 46 LLDB 0x0000000102ebdb91 lldb::SBDebugger::RunCommandInterpreter(bool, bool) + 209 47 lldb 0x0000000102dfe665 Driver::MainLoop() + 2853 48 lldb 0x0000000102dff5d2 main + 1634 49 libdyld.dylib 0x00007fff6c85d7fd start + 1 50 libdyld.dylib 0x000000000000000f start + 2474256403 Stack dump: 0. Program arguments: /Applications/Xcode.app/Contents/Developer/usr/bin/lldb -o settings set plugin.process.gdb-remote.target-definition-file Scripts/x86_64_target_definition.py -o gdb-remote 8864 -o target modules add -s GdbSyms/Bin/X64_CLANGPDB/GdbSyms.pdb GdbSyms/Bin/X64_CLANGPDB/GdbSyms.dll -o command script import Scripts/lldb_uefi.py -o command script add -c lldb_uefi.ReloadUefi reload-uefi -o reload-uefi -o b DebugBreak ./maclldb.tool: line 33: 37722 Segmentation fault: 11 "$LLDB" -o "settings set plugin.process.gdb-remote.target-definition-file Scripts/x86_64_target_definition.py" -o "gdb-remote $LLDB_PORT" -o "target modules add -s GdbSyms/Bin/X64_CLANGPDB/GdbSyms.pdb GdbSyms/Bin/X64_CLANGPDB/GdbSyms.dll" -o "command script import Scripts/lldb_uefi.py" -o "command script add -c lldb_uefi.ReloadUefi reload-uefi" -o "reload-uefi" -o "b DebugBreak"