MIsleading diagnostic and crash when executing named macro

void misleadingDiag(){

   TThread::Initialize();

   TH1::AddDirectory(kFALSE);

   ROOT::Math::MinimizerOptions::SetDefaultMinimizer("Minuit2");

   vector<thread> threads;

   TRandom3 rndm;

   for (int i=0;i<5;++i){

      auto f = [&](){

         TH1F h("h","h",100,-1,1);

         for (/*int*/ j=0;j<100;++j){

            h.Fill(rndm.Gaus(-1,1));

         }

         h.Fit("gaus");

      };

      threads.emplace_back(f);

   }

   for (auto&& t : threads) t.join();

}

Processing misleadingDiag.C...

warning: expression result unused [-Wunused-value]

 *** Break *** segmentation violation

===========================================================

There was a crash (kSigSegmentationViolation).

This is the entire stack trace of all threads:

===========================================================

#0  0x00007fa3c17fd6dc in __libc_waitpid (pid=1817, stat_loc=stat_loc

entry=0x7fff62d23710, options=options

entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:31

#1  0x00007fa3c17822e2 in do_system (line=<optimized out>) at ../sysdeps/posix/system.c:148

#2  0x00007fa3c2fcd009 in TUnixSystem::Exec (this=0x7fa3c082d300, shellcmd=0x7fa3b4496800 "/ssd/RootDevel/Root6/head/buildClang/etc/gdb-backtrace.sh 1796 1>&2") at /home/dpiparo/RootDevel/Root6/head/root/core/unix/src/TUnixSystem.cxx:2069

#3  0x00007fa3c2fcdbe5 in TUnixSystem::StackTrace (this=0x7fa3c082d300) at /home/dpiparo/RootDevel/Root6/head/root/core/unix/src/TUnixSystem.cxx:2297

#4  0x00007fa3c2fd3729 in TUnixSystem::DispatchSignals (this=0x7fa3c082d300, sig=kSigSegmentationViolation) at /home/dpiparo/RootDevel/Root6/head/root/core/unix/src/TUnixSystem.cxx:3535

#5  0x00007fa3c2fc7ea4 in SigHandler (sig=kSigSegmentationViolation) at /home/dpiparo/RootDevel/Root6/head/root/core/unix/src/TUnixSystem.cxx:395

#6  0x00007fa3c2fd38f7 in sighandler (sig=11) at /home/dpiparo/RootDevel/Root6/head/root/core/unix/src/TUnixSystem.cxx:3512

#7  0x00007fa3c2fc76c6 in textinput::TerminalConfigUnix::HandleSignal (this=0x7fa3c3346cd8 <textinput::TerminalConfigUnix::Get()::s>, signum=11) at /home/dpiparo/RootDevel/Root6/head/root/core/textinput/src/textinput/TerminalConfigUnix.cpp:96

#8  0x00007fa3c2fc74bb in (anonymous namespace)::TerminalConfigUnix__handleSignal (signum=11) at /home/dpiparo/RootDevel/Root6/head/root/core/textinput/src/textinput/TerminalConfigUnix.cpp:36

#9  <signal handler called>

#10 0x00007fa3bf769c0d in llvm::LoadInst::LoadInst(llvm::Value*, char const*, bool, llvm::Instruction*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#11 0x00007fa3be8de0f5 in llvm::IRBuilder<false, llvm::ConstantFolder, clang::CodeGen::CGBuilderInserter<false> >::CreateLoad(llvm::Value*, llvm::Twine const&) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#12 0x00007fa3be9b0fe5 in clang::CodeGen::CodeGenFunction::EmitLoadOfScalar(llvm::Value*, bool, unsigned int, clang::QualType, clang::SourceLocation, llvm::MDNode*, clang::QualType, unsigned long) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#13 0x00007fa3be9b26a7 in clang::CodeGen::CodeGenFunction::EmitLoadOfLValue(clang::CodeGen::LValue, clang::SourceLocation) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#14 0x00007fa3be9d18a3 in clang::StmtVisitorBase<clang::make_ptr, (anonymous namespace)::ScalarExprEmitter, llvm::Value*>::Visit(clang::Stmt*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#15 0x00007fa3be9d6985 in (anonymous namespace)::ScalarExprEmitter::VisitCastExpr(clang::CastExpr*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#16 0x00007fa3be9d86ae in (anonymous namespace)::ScalarExprEmitter::EmitCompare(clang::BinaryOperator const*, unsigned int, unsigned int, unsigned int) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#17 0x00007fa3be9c8ae6 in clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#18 0x00007fa3be9a6b26 in clang::CodeGen::CodeGenFunction::EvaluateExprAsBool(clang::Expr const*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#19 0x00007fa3be8d7a9d in clang::CodeGen::CodeGenFunction::EmitForStmt(clang::ForStmt const&, llvm::ArrayRef<clang::Attr const*>) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#20 0x00007fa3be8d5f7d in clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#21 0x00007fa3be8dc72b in clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#22 0x00007fa3be8f0b22 in clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#23 0x00007fa3be8fdc12 in clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#24 0x00007fa3be8fae7c in clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#25 0x00007fa3be8f68d1 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#26 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#27 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#28 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#29 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#30 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#31 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#32 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#33 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#34 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#35 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#36 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#37 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#38 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#39 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#40 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#41 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#42 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#43 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#44 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#45 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#46 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#47 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#48 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#49 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#50 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#51 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#52 0x00007fa3be8f68f9 in clang::CodeGen::CodeGenModule::EmitDeferred() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#53 0x00007fa3be8f64d3 in clang::CodeGen::CodeGenModule::Release() () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#54 0x00007fa3be3f8de0 in cling::IncrementalParser::codeGenTransaction(cling::Transaction*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#55 0x00007fa3be3f8880 in cling::IncrementalParser::commitTransaction(cling::Transaction*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#56 0x00007fa3be3f953e in cling::IncrementalParser::Compile(llvm::StringRef, cling::CompilationOptions const&) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#57 0x00007fa3be3a7842 in cling::Interpreter::declare(std::string const&, cling::Transaction**) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#58 0x00007fa3be3aad45 in cling::Interpreter::loadFile(std::string const&, bool, cling::Transaction**) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#59 0x00007fa3be4292c0 in cling::MetaSema::actOnLCommand(llvm::StringRef, cling::Transaction**) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#60 0x00007fa3be429bf8 in cling::MetaSema::actOnxCommand(llvm::StringRef, llvm::StringRef, cling::Value*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#61 0x00007fa3be43739c in cling::MetaParser::isXCommand(cling::MetaSema::ActionResult&, cling::Value*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#62 0x00007fa3be436a45 in cling::MetaParser::isCommand(cling::MetaSema::ActionResult&, cling::Value*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#63 0x00007fa3be436835 in cling::MetaParser::isMetaCommand(cling::MetaSema::ActionResult&, cling::Value*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#64 0x00007fa3be4279a6 in cling::MetaProcessor::process(char const*, cling::Interpreter::CompilationResult&, cling::Value*) () from /ssd/RootDevel/Root6/head/buildClang/lib/libCling.so

#65 0x00007fa3be24341c in TCling::ProcessLine (this=0x7fa3c082d600, line=0x7fa3b48623c0 ".X  /home/dpiparo/./misleadingDiag.C", error=0x7fff62d2d4b4) at /home/dpiparo/RootDevel/Root6/head/root/core/meta/src/TCling.cxx:1889

#66 0x00007fa3be2476cf in TCling::ProcessLineSynch (this=0x7fa3c082d600, line=0x7fa3b48623c0 ".X  /home/dpiparo/./misleadingDiag.C", error=0x7fff62d2d4b4) at /home/dpiparo/RootDevel/Root6/head/root/core/meta/src/TCling.cxx:2641

#67 0x00007fa3c2ec5e1d in TApplication::ExecuteFile (file=0x7fff62d2b433 "misleadingDiag.C", error=0x7fff62d2d4b4, keep=false) at /home/dpiparo/RootDevel/Root6/head/root/core/base/src/TApplication.cxx:1114

#68 0x00007fa3c2ec5190 in TApplication::ProcessFile (this=0x7fa3c08a83c0, file=0x7fff62d2b433 "misleadingDiag.C", error=0x7fff62d2d4b4, keep=false) at /home/dpiparo/RootDevel/Root6/head/root/core/base/src/TApplication.cxx:990

#69 0x00007fa3c2ec4e78 in TApplication::ProcessLine (this=0x7fa3c08a83c0, line=0x7fff62d2b430 ".x misleadingDiag.C", sync=false, err=0x7fff62d2d4b4) at /home/dpiparo/RootDevel/Root6/head/root/core/base/src/TApplication.cxx:963

#70 0x00007fa3c25619e1 in TRint::ProcessLineNr (this=0x7fa3c08a83c0, filestem=0x7fa3c2573dbf "ROOT_cli_", line=0x7fff62d2b430 ".x misleadingDiag.C", error=0x7fff62d2d4b4) at /home/dpiparo/RootDevel/Root6/head/root/core/rint/src/TRint.cxx:740

#71 0x00007fa3c2561433 in TRint::Run (this=0x7fa3c08a83c0, retrn=false) at /home/dpiparo/RootDevel/Root6/head/root/core/rint/src/TRint.cxx:416

#72 0x0000000000401357 in main (argc=1, argv=0x7fff62d2d618) at /home/dpiparo/RootDevel/Root6/head/root/main/src/rmain.cxx:29