util.inspect({level: "info"}) exits the debug session

[learnerbyheart]

When debugging in node.js 5.3.0 the script bug.js

var util = require('util');
util.inspect({level: "info "});
console.log("Test");

with node debug bug.js, the debugging session exits. I tried the same in node.js 4.2.4 and it doesn't. When debugging the difference in lib/util.js, line 324 in 5.3.0 looks like this:

var promiseInternals = inspectPromise(value);

and line 319 in 4.2.4 looks like:

var promiseInternals = value instanceof Promise && inspectPromise(value);

As value is not an instance of Promise, inspectPromise(value) is called in 5.3.0. Then inspectPromise calls ensureDebugIsInitialized() which on the other hand calls require('vm').runInDebugContext('Debug'). This causes the debugging session to exit. The issue was tested in Ubuntu 14.04 LTS.

[mscdex]

Can you clarify what you're doing step-by-step? You mention running that script with node debug but where does the util.inspect({level: 'info'}) come into play? I ran the script as you say, it breaks on the first statement and continuing execution at the debug> prompt results in "Finished" logged to stdout as expected.

[learnerbyheart]

Sorry, that was an copy and paste fault by me. I updated my initial comment where the right bug.js script is described.

[learnerbyheart]

But the before mentioned script bug2.js

var vm = require('vm');
vm.runInDebugContext('Debug');
console.log("Finished");

exits after vm.runInDebugContext('Debug'); when I run node debug bug2.js.

[mscdex]

I'm not able to reproduce that on master:

$ cat bug.js 
var vm = require('vm');
vm.runInDebugContext('Debug');
console.log("Finished");
$ ./node debug bug.js
< Debugger listening on port 5858
connecting to 127.0.0.1:5858 ... ok
break in bug.js:1
> 1 var vm = require('vm');
  2 vm.runInDebugContext('Debug');
  3 console.log("Finished");
debug> c
< Finished
debug> .exit

[mscdex]

Similarly with your updated code example, I cannot reproduce the problem there either on master:

$ cat bug2.js 
var util = require('util');
util.inspect({level: "info "});
console.log("Test");
$ ./node debug bug2
< Debugger listening on port 5858
connecting to 127.0.0.1:5858 ... ok
break in bug2.js:1
> 1 var util = require('util');
  2 util.inspect({level: "info "});
  3 console.log("Test");
debug> c
< Test
debug> .exit

[mscdex]

Perhaps there's something that needs to be backported to 5.x yet?

[learnerbyheart]

I debugged the script

var vm = require('vm');
vm.runInDebugContext('Debug');
console.log("Finished");

in a new workspace in cloud9 (https://c9.io/) which has node 4.1.1 and Ubuntu 14.04 LTS, on my private Laptop which has node 5.3.0 and Ubuntu 15.10 and on a new VM with a fresh Ubuntu 14.04 LTS and node 4.2.4. In every environment the debugging exits after vm.runInDebugContext('Debug');. Usually I code in WebStorm which exited with exit code 139 when debugging it. When debugging it via node-inspector as well with cloud9 the error message was a segmentation fault.
Does it has something to do with Ubuntu as the operating system? Which os did you use? Does the master branch differs from the 5.3.0 tag?

[mscdex]

Yes, master represents the next major version. Necessary commits are backported to versioned branches (e.g. v4.x, v5.x, etc.).

It shouldn't be OS-related. I don't know offhand what needs to be backported, there's a fair amount of different stuff in master (including a new "major" v8 version).

[Trott]

On OSX, it's broken for me in Node 5.3.0 but works fine with current master.

5.3.0:

$ cat test.js
var vm = require('vm');
vm.runInDebugContext('Debug');
console.log("Finished");
$ node debug test.js 
< Debugger listening on port 5858
connecting to 127.0.0.1:5858 ... ok
break in test.js:1
> 1 var vm = require('vm');
  2 vm.runInDebugContext('Debug');
  3 console.log("Finished");
debug> c
program terminated
debug> .exit

master:

$ ~/io.js/node debug test.js 
< Debugger listening on port 5858
connecting to 127.0.0.1:5858 ... ok
break in test.js:1
> 1 var vm = require('vm');
  2 vm.runInDebugContext('Debug');
  3 console.log("Finished");
debug> c
< Finished
debug> .exit

[Trott]

Maybe it was fixed by 25776f3?

[bnoordhuis]

25776f3 is almost certainly the fix. (EDIT: And hasn't been released yet.)

[learnerbyheart]

In which release will it be inculded? 5.4.0? When will this release be published?

[Trott]

@LucasMoody It should be in the next release which will either be 5.3.1 or 5.4.0 depending on what else is in the release.

For the stable release line (currently 5.x), the goal is to have a release every 1-2 weeks. The release team seems to be meeting that goal. There's probably not much activity this week, though, as it's a major holiday in much of the world. So add one more week maybe.

So, the unofficial upshot from my non-release-team-member analysis would be: A release with the fix should be out by January 15, and probably sooner.

[cjihrig]

I'm going to close this as it appears to be fixed in master. As @Trott mentioned, a new release should be out soon - almost certainly before January 15.

[learnerbyheart]

Hey, after I cloned the Master branch and installed node, I debugged the following util-bug.js script:

var util = require('util');
util.inspect({level: "info"});
1 + 1;
2 + 2;
console.log("Finished");

After setting a breakpoint in line 4 with sb(4) and entering c the debugger doesn't show the source code anymore, even if I type list(5). After typing list(5) the debugger frozes. As described in my first post, I guess node.inspect executes vm.runInDebugContext('Debug'). I'm not quite sure what vm.runInDebugContext does, but after executing the line in debug mode, I cannot debug further (continue to breakpoints, list source code, etc.). Could you please reopen the issue and take a look at this.
Best regards,
Lucas

[Trott]

Re-opening as requested. If someone else feels like this ought to remain closed and a new issue opened instead, feel free to close and comment to that effect. It does seem like this is a new issue that was masked by the first issue.

[atom0s]

I see this issue happening while using 5.3.0 with this node module: https://github.com/Azure/azure-storage-node

While checking for a container on Azure, the module will call:

self.logger.log(Logger.LogLevels.DEBUG, 'FINAL REQUEST OPTIONS:\n' + util.inspect(finalRequestOptions));

Which results in a crash at the same location that @LucasMoody mentioned. It will eventually get down to:
util.js

var promiseInternals = inspectPromise(value);

And crash here:
vm.js

exports.runInDebugContext = function(code) {
    return binding.runInDebugContext(code);
};

If it helps with debugging this problem, the logger that azure sets up in that module is done like this:

var Logger = require('../diagnostics/logger');
this.logger = new Logger(Logger.LogLevels.INFO);

Their logger can be seen here:
https://github.com/Azure/azure-storage-node/blob/master/lib/common/diagnostics/logger.js

[cohowap]

This does seem to still exist on Node 5.4.0. I am seeing exactly what @atom0s is seeing.

[learnerbyheart]

Hey @mscdex and @Trott,
is there any update on this issue? There has not been any messages for 2 weeks.

[Trott]

I don't know that anyone is actively working on this issue. (If someone is, hey, speak up here, will ya?)

I'm not sure who the key contacts would be for the debugger, but judging from the commit logs, I'd guess @indutny. Not sure if he has sufficient spare time and inclination to dive into this issue, but if not, maybe he can at least point someone in the right general direction.

If you're feeling like you might want to take a shot at solving the problem yourself, then (absent suggestions from other people who are more informed than I am) I'd start by looking at these files in the source code repo:

lib/_debug_agent.js
lib/_debugger.js
src/debug-agent.cc
src/debug-agent.h

Hopefully @mscdex or someone else will have something more helpful to offer, but for the moment, that's what I've got.

[mscdex]

I have no idea either offhand what the change was. You could git bisect it I suppose.

[daef]

i'm experiencing this issue when debugging my expressjs application via node-debug (node 5.4.1)

express logs a value, the formatter tries to inspect the value via inspectPromise, which calls ensureDebugIsInitialized and my debugging session is gone

any workarounds?

[AdamAndersonFalafelSoftware]

I also experienced this problem on Windows 10. Downgrading to Node 4.2.4 (and then installing the latest NPM to avoid MAX_PATH issues) worked around the issue for me.

[MylesBorins]

I bet this is the same problem we are seeing in #4815

[jasnell]

From what I've been able to investigate @thealphanerd ... I tend to agree.

[guidoman]

Similar behavior described by @imaustink with Webstorm under OS X with 4.2.6. Node 4.2.2 is working OK.

[MylesBorins]

There is a fix in, hoping to have it released for ya'll soon after the next security release

#4819

[mikermcneil]

Thanks @thealphanerd!

In the mean time, for folks stumbling upon this, I can confirm that downgrading to 4.2.4 resolves this for folks seeing issues in their Sails apps (thanks @chirag200666 and @LongSteve!)

[MylesBorins]

The fix is now in master, you should expect this to see it in a release in the next 2 - 3 weeks on v4 and v5.

[atom0s]

Thanks for your efforts @thealphanerd it is greatly appreciated.

[MylesBorins]

The fix is now released in v5.6.0. Expect LTS next week

[Smurf-IV]

Still broken in 4.3.0
with the following code in WebStorm 11.03 debug

        var jsonData = jsonfile.readFileSync(fromFile);
        log.trace(jsonData);

The trace (or info levels etc) is dumped, but the debug session is exited afterwards.

[atom0s]

The comment just above yours mentioned already that it will be fixed at a later time for LTS.

[jasnell]

Yes, v4.3.0 was a security fix that only included the fixes for the
security issues. It bumped all other fixes to the next LTS release which
we'll be working on soon.
On Feb 11, 2016 1:35 AM, "atom0s" notifications@github.com wrote:

The comment just above yours mentioned already that it will be fixed at a
later time for LTS.

—
Reply to this email directly or view it on GitHub
#4440 (comment).

[rainabba]

This isn't TOP priority? #4382

[MylesBorins]

As mentioned above 4.3.1 has been released with the fix for this bug!