ROOT crashes when creating a TCanvas with gDebug=1

On MacOS, this results in a ROOT crash:

 

root[0]  gDebug = 1;

root[1]  new TCanvas(); 

 

....................................

Info in <TPluginManager::FindHandler>: found plugin for TRootGuiFactory

2020-08-19 17:09:42.012 root.exe[84287:3648601] Fatal error: requested non-existing drawable 1

2020-08-19 17:09:42.012 root.exe[84287:3648601] This drawable not found among allocated/deleted drawables

 

 *** Break *** segmentation violation

[/usr/lib/system/libsystem_platform.dylib] _sigtramp (no debug info)

[/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation] CreateStringFromFileSystemRepresentationByAddingPercentEscapes.hexchars (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGui.so] TGWindow::SetWindowName(char const*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGui.so] TGFrame::TGFrame(TGClient*, unsigned long, TGWindow const*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGui.so] TGClient::TGClient(char const*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGui.so] TRootApplication::TRootApplication(char const*, int*, char**) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGui.so] TRootGuiFactory::CreateApplicationImp(char const*, int*, char**) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCore.so] TApplication::InitializeGraphics() (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGpad.so] TCanvas::Init() (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGpad.so] TCanvas::Constructor(char const*, char const*, int) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libGpad.so] TCanvas::TCanvas(bool) (no debug info)

[<unknown binary>] (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] cling::IncrementalExecutor::executeWrapper(llvm::StringRef, cling::Value*) const (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] cling::Interpreter::RunFunction(clang::FunctionDecl const*, cling::Value*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] cling::Interpreter::EvaluateInternal(std::_1::basic_string<char, std::1::char_traits<char>, std::_1::allocator<char> > const&, cling::CompilationOptions, cling::Value*, cling::Transaction**, unsigned long) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] cling::Interpreter::process(std::_1::basic_string<char, std::1::char_traits<char>, std::_1::allocator<char> > const&, cling::Value*, cling::Transaction**, bool) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] cling::MetaProcessor::process(llvm::StringRef, cling::Interpreter::CompilationResult&, cling::Value*, bool) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] HandleInterpreterException(cling::MetaProcessor*, char const*, cling::Interpreter::CompilationResult&, cling::Value*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCling.so] TCling::ProcessLine(char const*, TInterpreter::EErrorCode*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libRint.so] TRint::ProcessLineNr(char const*, char const*, int*) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libRint.so] TRint::HandleTermInput() (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCore.so] TUnixSystem::CheckDescriptors() (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCore.so] TMacOSXSystem::DispatchOneEvent(bool) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCore.so] TSystem::InnerLoop() (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCore.so] TSystem::Run() (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libCore.so] TApplication::Run(bool) (no debug info)

[/Users/moneta/root/git/root_dev2-build/lib/libRint.so] TRint::Run(bool) (no debug info)

[/Users/moneta/root/git/root_dev2-build/bin/root.exe] main (no debug info)

[/usr/lib/system/libdyld.dylib] start (no debug info)

[<unknown binary>] (no debug info)