Repro:

Evaluate this in the console:
  debug(window.fetch);
  await fetch('https://api.github.com/search/repositories?q=user:developit');

When it's paused, click step into.
Renderer crashes.

You can also reproduce this when stepping into `fetch` method regularly debugging.


Stack trace:
[75668:775:0507/122444.716067:FATAL:v8_per_isolate_data.cc(52)] Check failed: !ScriptForbiddenScope::IsScriptForbidden().
0   libbase.dylib                       0x00000001067726bc base::debug::StackTrace::StackTrace(unsigned long) + 28
1   libbase.dylib                       0x0000000106794adf logging::LogMessage::~LogMessage() + 223
2   libblink_platform.dylib             0x000000011612b7c2 blink::BeforeCallEnteredCallback(v8::Isolate*) + 98
3   libv8.dylib                         0x00000001051454a5 v8::Function::Call(v8::Local<v8::Context>, v8::Local<v8::Value>, int, v8::Local<v8::Value>*) + 341
4   libv8.dylib                         0x00000001059482c9 v8_inspector::V8FunctionCall::callWithoutExceptionHandling() + 377
5   libv8.dylib                         0x0000000105948123 v8_inspector::V8FunctionCall::call(bool&, bool) + 67
6   libv8.dylib                         0x0000000105918cae v8_inspector::InjectedScript::wrapValue(v8::Local<v8::Value>, v8_inspector::String16 const&, bool, bool, v8::Local<v8::Value>*) const + 222
7   libv8.dylib                         0x0000000105918a07 v8_inspector::InjectedScript::wrapObject(v8::Local<v8::Value>, v8_inspector::String16 const&, bool, bool, std::__1::unique_ptr<v8_inspector::protocol::Runtime::RemoteObject, std::__1::default_delete<v8_inspector::protocol::Runtime::RemoteObject> >*) const + 119
8   libv8.dylib                         0x0000000105935ea2 v8_inspector::V8DebuggerAgentImpl::currentCallFrames(std::__1::unique_ptr<v8_inspector::protocol::Array<v8_inspector::protocol::Debugger::CallFrame>, std::__1::default_delete<v8_inspector::protocol::Array<v8_inspector::protocol::Debugger::CallFrame> > >*) + 850
9   libv8.dylib                         0x0000000105931595 v8_inspector::V8DebuggerAgentImpl::didPause(int, v8::Local<v8::Value>, std::__1::vector<int, std::__1::allocator<int> > const&, bool, bool, bool, bool) + 1845
10  libv8.dylib                         0x0000000105944f4e _ZNSt3__110__function6__funcIZN12v8_inspector10V8Debugger18handleProgramBreakEN2v85LocalINS4_7ContextEEENS5_INS4_5ValueEEERKNS_6vectorIiNS_9allocatorIiEEEEbbE3$_1NSB_ISG_EEFvPNS2_22V8InspectorSessionImplEEEclEOSJ_ + 110
11  libv8.dylib                         0x000000010595003e v8_inspector::V8InspectorImpl::forEachSession(int, std::__1::function<void (v8_inspector::V8InspectorSessionImpl*)>) + 1198
12  libv8.dylib                         0x00000001059401b0 v8_inspector::V8Debugger::handleProgramBreak(v8::Local<v8::Context>, v8::Local<v8::Value>, std::__1::vector<int, std::__1::allocator<int> > const&, bool, bool) + 816
13  libv8.dylib                         0x00000001054536b0 v8::internal::Debug::OnDebugBreak(v8::internal::Handle<v8::internal::FixedArray>) + 784
14  libv8.dylib                         0x00000001054597de v8::internal::Debug::HandleDebugBreak(v8::internal::IgnoreBreakMode) + 814
15  libv8.dylib                         0x0000000105158659 v8::debug::BreakRightNow(v8::Isolate*) + 41
16  libv8.dylib                         0x0000000105940dfe v8_inspector::V8Debugger::asyncTaskCandidateForStepping(void*, bool) + 254
17  libv8.dylib                         0x0000000105943dc4 v8_inspector::V8Debugger::asyncTaskScheduled(v8_inspector::StringView const&, void*, bool) + 84
 

Deleted: Screen Shot 2018-05-07 at 12.26.25 PM.png 178 KB

	Screen Shot 2018-05-07 at 12.26.25 PM.png 178 KB View Download