In https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Win10%20Debug%20%28NVIDIA%29/10841, a number of tests failed in what appears to be a problem initializing V8. The logs contain:

# Fatal error in ../../v8/src/snapshot/deserializer.cc, line 671
# Debug check failed: too few external references provided through the API.

and stacks along the lines of:

acktrace:
	base::win::SetAbortBehaviorForCrashReporting [0x7396A317+87]
	raise [0x72D7F82B+875]
	v8::base::OS::Abort [0x0BDA49A3+51]
	V8_Fatal [0x0BD97911+209]
	v8::base::SetDcheckFunction [0x0BD97676+54]
	v8::internal::Deserializer::ReadData [0x5733417D+1485]
	v8::internal::Deserializer::ReadObject [0x57336FCF+223]
	v8::internal::Deserializer::ReadDataCase<0,0,0,-1> [0x57337319+41]
	v8::internal::Deserializer::ReadData [0x57334537+2439]
	v8::internal::Deserializer::ReadObject [0x57336FCF+223]
	v8::internal::Deserializer::ReadDataCase<0,0,0,-1> [0x57337319+41]
	v8::internal::Deserializer::ReadData [0x57334537+2439]
	v8::internal::Deserializer::ReadObject [0x57336FCF+223]
	v8::internal::Deserializer::ReadDataCase<0,0,0,-1> [0x57337319+41]
	v8::internal::Deserializer::ReadData [0x57334537+2439]
	v8::internal::Deserializer::ReadObject [0x57336FCF+223]
	v8::internal::Deserializer::ReadDataCase<0,0,0,-1> [0x57337319+41]
	v8::internal::Deserializer::ReadData [0x57334537+2439]
	v8::internal::Deserializer::ReadObject [0x57336FCF+223]
	v8::internal::Deserializer::ReadDataCase<0,0,0,-1> [0x57337319+41]
	v8::internal::Deserializer::ReadData [0x57334537+2439]
	v8::internal::Deserializer::VisitRootPointers [0x57333BA2+18]
	v8::internal::Heap::IterateStrongRoots [0x56F1DF6D+77]
	v8::internal::StartupDeserializer::DeserializeInto [0x5735F521+209]
	v8::internal::Isolate::Init [0x5704771F+2799]
	v8::internal::Snapshot::Initialize [0x5735CD51+321]
	v8::Isolate::Initialize [0x569F85CD+317]
	gin::IsolateHolder::IsolateHolder [0x5694BA10+1264]
	blink::V8PerIsolateData::V8PerIsolateData [0x50EA5A2B+171]
	blink::V8PerIsolateData::Initialize [0x50EA68A7+183]
	blink::V8Initializer::InitializeMainThread [0x5346774D+557]
	logging::LogMessage::stream [0x0F9B16DE+462]
	blink::Initialize [0x0F9B10DF+223]
	content::RenderThreadImpl::InitializeWebKit [0x63C12531+385]
	content::RenderThreadImpl::Init [0x63C0FBAC+1420]
	content::RenderThreadImpl::RenderThreadImpl [0x63C11FA5+2677]
	content::RendererMain [0x63C9E1FA+1594]
	content::RunOtherNamedProcessTypeMain [0x63F8C6CF+175]
	content::ContentMainRunnerImpl::Run [0x63F8D6C5+645]
	content::ContentServiceManagerMainDelegate::RunEmbedderProcess [0x63F8A692+50]
	service_manager::Main [0x0A5536DA+1786]
	content::ContentMain [0x63F8C4EC+92]
	ChromeMain [0x663F132D+493]
	MainDllLoader::Launch [0x002CA6BD+1101]
	wWinMain [0x002C1475+1141]
	invoke_main [0x0051B1EE+30] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:123)
	__scrt_common_main_seh [0x0051B341+337] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283)
	__scrt_common_main [0x0051B40D+13] (f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:326)
	wWinMainCRTStartup [0x0051B418+8] (f:\dd\vctools\crt\vcstartup\src\startup\exe_wwinmain.cpp:17)
	BaseThreadInitThunk [0x75578674+36]
	RtlGetAppContainerNamedObjectPath [0x771D5D87+311]
	RtlGetAppContainerNamedObjectPath [0x771D5D57+263]

In some cases, the output is difficult to read due to interleaving of multiple streams.