VM Crash while debugging - 2.1.0-dev.0.0 - si_signo=Segmentation fault: 11(11), si_code=1, si_addr=0x54b17a9c0

[kevmoo]

Here's the repo I've found. Notice the line below where the breakpoint should be placed!

import 'dart:async';

main() async {
  print(
      await pooledIterator(10, Iterable<int>.generate(10, (i) => i), _getValue)
          .toList());
}

Future<int> _getValue(int i) async {
  // Commenting out the next line avoids the crash
  await Future.delayed(const Duration(milliseconds: 1));

  // Put breakpoint on the next line
  return i * 10;
}

Stream<T> pooledIterator<S, T>(
  int poolSize,
  Iterable<S> sourceItems,
  Future<T> action(S source),
) async* {
  final controller = StreamController<T>();

  final items = Future.wait(sourceItems.map((item) async {
    controller.add(await action(item));
  })).whenComplete(() async {
    await controller.close();
  });

  yield* controller.stream;

  await items;
}

===== CRASH =====
version=2.2.0-edge.644d92497878d19a1445f05649caa79da6e774b3 (Mon Dec 10 14:56:15 2018 +0000) on "macos_x64"
si_signo=Segmentation fault: 11(11), si_code=1, si_addr=0x5409bded8
thread=10247, isolate=i34134_test.dart:main()(0x7f8b23053e00)
  [0x000000010acefd93] dart::ActivationFrame::GetAsyncStreamControllerStreamAwaiter(dart::Object const&)
  [0x000000010acefd93] dart::ActivationFrame::GetAsyncStreamControllerStreamAwaiter(dart::Object const&)
  [0x000000010acecae1] dart::Debugger::CollectAwaiterReturnStackTrace()
  [0x000000010acf915a] dart::Debugger::PauseBreakpoint()
  [0x000000010ae3d95f] dart::DRT_BreakpointRuntimeHandler(dart::NativeArguments)
  [0x000000010c240f42] Unknown symbol
  [0x000000010c241ee1] Unknown symbol
  [0x000000010effda2f] Unknown symbol
  [0x00000001104cde2f] Unknown symbol
  [0x00000001104cda06] Unknown symbol
  [0x00000001104cd645] Unknown symbol
  [0x00000001104cc7b9] Unknown symbol
  [0x00000001104cb18c] Unknown symbol
  [0x00000001104cabd1] Unknown symbol
  [0x00000001104ca9f9] Unknown symbol
  [0x000000010efc98d9] Unknown symbol
  [0x00000001104c9b11] Unknown symbol
  [0x00000001104c7af8] Unknown symbol
  [0x00000001104c76da] Unknown symbol
  [0x000000010efc98d9] Unknown symbol
  [0x000000010efe7d70] Unknown symbol
  [0x000000010c2413a6] Unknown symbol
  [0x000000010ace68b0] dart::DartEntry::InvokeFunction(dart::Function const&, dart::Array const&, dart::Array const&, unsigned long)
  [0x000000010ace985f] dart::DartLibraryCalls::HandleMessage(dart::Object const&, dart::Instance const&)
  [0x000000010ad1810b] dart::IsolateMessageHandler::HandleMessage(dart::Message*)
  [0x000000010ad4774e] dart::MessageHandler::HandleMessages(dart::MonitorLocker*, bool, bool)
  [0x000000010ad47dc6] dart::MessageHandler::TaskCallback()
  [0x000000010ae854df] dart::ThreadPool::Worker::Loop()
  [0x000000010ae85367] dart::ThreadPool::Worker::Main(unsigned long)
  [0x000000010ade3777] dart::OSThread::GetMaxStackSize()
  [0x00007fff5f3bf661] _pthread_body
  [0x00007fff5f3bf50d] _pthread_body
  [0x00007fff5f3bebf9] thread_start
-- End of DumpStackTrace

[a-siva]

Can you provide any information about how to reproduce this or a description of what you were doing when this happened.

[kevmoo]

Hitting this again with 2.2.0-edge. 644d924 and 2.2.0-dev.0.0

I can reproduce, @a-siva if someone wants to look!

[kevmoo]

Seems to be related to setting a breakpoint within a async* function. Will try to get a repro.

[kevmoo]

Updated the first comment w/ a repro (that doesn't require a package)

[aam]

Thanks for the repro.
I tried reproducing the crash in observatory launching the test from command line out/ReleaseX64/dart --observe --pause-isolates-on-start crash-34134.dart , setting breakpoint line 14, resuming and continuing through the breakpoints. The test completes successfully for me.
This is on 2.2.0-edge.679108ea7b807efd92167c8ba8e99395f9d3b8d3.

[kevmoo]

I'm using IntelliJ to debug this

…

On Tue, Dec 11, 2018 at 9:35 AM Alexander Aprelev ***@***.***> wrote: Thanks for the repro. I tried reproducing the crash in observatory launching the test from command line out/ReleaseX64/dart --observe --pause-isolates-on-start crash-34134.dart , setting breakpoint line 14, resuming and continuing through the breakpoints. The test completes successfully for me. This is on 2.2.0-edge.679108ea7b807efd92167c8ba8e99395f9d3b8d3. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#34134 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AABCim7mJYoirqt6b7vltDh5i_YpsAMxks5u3-zKgaJpZM4V7FKu> .

[aam]

Just tried IJ on Linux(with dart sdk pointing to the same 2.2.0-edge.679108ea7b807efd92167c8ba8e99395f9d3b8d3), set up breakpoint at return i * 10, started, resumed after breakpoint was hit and saw the program complete fine.

Does it crash on the first breakpoint hit for you? Is this on Linux/Mac/Windows?

[kevmoo]

1. See the updated repro. You need the await Future.delayed
2. mac
3. I set a breakpoint in IntelliJ and it crashes without ever getting to the breakpoint

[aam]

Okay with line 11 uncommented, I am able to repro the crash.

[aam]

Should be fixed at the head.