Segmentation fault: 11 when debug Promise

[3y3]

Segfault happens when I try to use evaluate command in non stopped process, which logs Promise to console.
node - latest 4 and 5
os - darwin x64

app.js

setInterval(console.log, 100, new Promise(() => {}));

pseudo debugger:

require('net').connect('5858', function() {
  var data = JSON.stringify({
    "seq": 1,
    "type": "request",
    "command": "evaluate",
    "arguments": {
      "global": true,
      "expression": "global"
    }
  });

  this.write(`Content-Length: ${Buffer.byteLength(data, 'utf8')}\r\n\r\n${data}`);
});

$ node --debug app.js
$ node debugger.js

All works fine if process is paused or I don't try to log Promise:

setInterval(() => {
  var p = new Promise(() => {});
  console.log(''); // works fine
}, 100)

Encapsulated test:

var app = require('child_process')
  .exec('node --debug -e "setInterval(console.log, 10, new Promise(() => {}))"')
  .on('exit', () => console.assert(app.signalCode !== 'SIGSEGV', 'Segmentation fault'));

app.stderr.on('data', () => /* wait for `Debugger listening on port 5858`*/
  setTimeout(() =>
    require('net').connect('5858', function() {
      var data = JSON.stringify({
        "seq": 1,
        "type": "request",
        "command": "evaluate",
        "arguments": {
          "global": true,
          "expression": "global" /* global is accessible in global scope */
        }
      });

      this.write(`Content-Length: ${Buffer.byteLength(data, 'utf8')}\r\n\r\n${data}`);
    }), 300 /* small delay to initialize debugger in app */));

[mscdex]

"node - latest 4 and 5" Can you be more specific about the exact versions you tried? 5.4.0 was just released the other day. Did you also try with the latest master branch?

[davidvgalbraith]

I just tried the latest master branch -- can confirm segfault.

[davidvgalbraith]

Ah, sorry, the line .exec('node --debug -e "setInterval(console.log, 10, new Promise(() => {}))"') ran my global node which is behind master. Does not segfault when I replace that node with ./node, so I think this duplicates #4261.

[mscdex]

I was able to duplicate it on OS X 10.10 with node v5.3.0, but not with v5.4.0.

Can you confirm @davidvgalbraith @3y3 ?

[davidvgalbraith]

I'm seeing the same thing @mscdex

[3y3]

Ok, sorry, I miss release of 5.4. I can't confirm segfault on 5.4, but code doesn't work correctly:
I add console.log for response from app. I expect two messages:
connection info

Type: connect
V8-Version: 4.6.85.31
Protocol-Version: 1
Embedding-Host: node v5.4.0
Content-Length: 0

and evaluation result, but I receive only connection info.

var app = require('child_process')
  .exec('node --debug -e "setInterval(console.log, 10, Promise.all())"')
  .on('exit', () => console.log(app, app.signalCode !== 'SIGSEGV', 'Segmentation fault'));

app.stderr.on('data', () =>
  setTimeout(() =>
    require('net').connect('5858', function() {
      var data = JSON.stringify({
        "seq": 1,
        "type": "request",
        "command": "evaluate",
        "arguments": {
          "global": true,
          "expression": "global" /* global is accessible in global scope */
        }
      });

      this.on('data', (data) => console.log('' + data));

      this.write(`Content-Length: ${Buffer.byteLength(data, 'utf8')}\r\n\r\n${data}`);

    }), 300 /* small delay to initialize debugger in app */));

[3y3]

@davidvgalbraith, @mscdex, is there any changes in debugger protocol in 5.4?

Is it possible to backport segfault fix in v4?

[3y3]

I also see the difference in debugger statement behavior (difference between 0.10 and latest versions)
In latest versions debugger pauses program if it was started with --debug flag. In 0.10 this happens only in there exists connected debugger.
Is it expected behavior @indutny ?

[mscdex]

@3y3 #4328 is already tagged for potential inclusion in v4.x.

[3y3]

Ok, I'm ready to close this issue and open one other about stalled debugger #4577 (comment)
Or I can rename this issue.

[mscdex]

@3y3 I would probably open a new issue and close this one.

[3y3]

Ready #4597