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Issue 3510 link

Starred by 20 users

Issue metadata

Status: WontFix
Closed: Dec 2017
HW: All
NextAction: ----
OS: ----
Priority: 2
Type: Bug

Blocked on:
issue 3270

issue 1543

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Harmony proxies are impossible to debug in tcp debugger (v8

Reported by, Aug 13 2014

Issue description


I've already reported this issue for node.js ( ), but it seems it originated from V8 itself. 

The situation is that if I have a breakpoint in a tcp based debugging session where the scope is behind a proxy call, then debuger hangs up, node console say "illegal access buff", and if I continue debugging it crashes with error: "Internal error: illegal access".

It happens in any debugger I tried: node-inspector, WebStorm, Nodeclipse.

I have a repro script:

var proxy = {
    create: function (target)
    return Proxy.create({
        has: function(name)
            return target[name] !== undefined;

        get: function (proxy, name)
            return target[name];

        set: function (proxy, name, value)
            target[name] = value;

        iterate: function* ()
            for (var p in target) yield p;

        enumerate: function ()
            return Object.keys(target);

function Foo()
{ = "Bimbi";
} = function()
    return; // Put a breakpoint here!

var fp = proxy.create(new Foo());

Repro steps by using node-inspector:

launch node-inspector
mocha --debug-brk --harmony repro.js
switch to node-inspector, refresh page, put a breakpoint to repro.js line 40
launch debugging
nothing happens, debugging hangs up (except there should be an error message in the node.js console that says: illegal access buff)
pause debugging
red Internal error: Illegal access will appear in the node-inspector console

There is an other version of this problem. It seems when the breakpoint is after a certain point in the scope far behind a proxy call, the debugging session won't hang up but the call stack will be broken, it will contains many "Internal error: Illegal access" entries instead of valid ones.

node 0.11.13 w/ v8

The above issue is not present in Chrome 36.0.1985.143 m with harmony flags, I can debug my proxies by using the bundled debugger.

Yup. Harmony proxies are not debugger-proof yet.

Comment 2 by, Aug 29 2014

Any plans/milestones to fix that?
Short answer: no. Proxies are generally lower priority for us than most other ES6 features, of which there are still plenty.
Labels: Type-Bug Harmony
Blocking: v8:1543
Labels: Area-Language Priority-Medium
Status: Assigned
I assume this one is fixed, right?
Blockedon: 3270
Labels: Priority-2

Comment 12 by, Dec 19 2017

Components: -Language Inspector
Labels: HW-All

Comment 13 by, Dec 19 2017

Status: WontFix (was: Assigned)
I can not reproduce it using modern proxy syntax. I believe this one is fixed.

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