vscode: Starting inspector on 127.0.0.1:9229 failed: address already in use with nodemon

Restart vscode didn’t help, but I’ve found a workaround for me.

1. run lsof -i:9229 to spot process occupying port 9229

com.docke   740 username   55u  IPv6 0x500cc99aa74d1278      0t0  TCP *:9229 (LISTEN)
Code\x20H 88376 username   49u  IPv4 0x511dd88ad7b5b676      0t0  TCP 127.0.0.1:9229 (LISTEN)

1. run kill 88376

2. vscode pop up an error : “Extension host terminated unexpectedly”

3. click Restart Extension on the error popup

4. Start your debugger again and hopefully it would work

a little bit hassle but works for me =)

Btw, my environment:

Version: 1.40.1
Electron: 6.1.2
Chrome: 76.0.3809.146
Node.js: 12.4.0
V8: 7.6.303.31-electron.0
OS: Darwin x64 19.0.0

It seems like this happens when there’s an extension that was updated and is awaiting a restart.

Also having the same issue here.

Run attach to process and show the error.

Look up the occupied port with lsof command:

lsof -i :9229

COMMAND     PID  USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
Code\x20H 20544 yukai   48u  IPv4 0xxxxxxxxxxxxxxxxx      0t0  TCP localhost:9229 (LISTEN)

And found that extension host process is listening to the port 9229

Applications/Visual Studio Code.app/Contents/Resources/app/out/bootstrap-fork --type=extensionHost

Restarting vscode worked for me!

    {
        "type": "node",
        "request": "launch",
        "name": "Next: Node",
        "runtimeExecutable": "next",
        "env": {
            "NODE_OPTIONS": "--inspect"
        },
        "port": 9229,
        "console": "integratedTerminal"
    }

the port really dont matter, always says failed: “address already in use”, and same with NPM runtime instead NODE

nextJS v8.0.3 node v12.8.1 npm v6.8.0

Debugger listening on ws://127.0.0.1:9229/828bbb76-a120-464b-9030-2555b1275b91 For help, see: https://nodejs.org/en/docs/inspector Debugger attached. Waiting for the debugger to disconnect… Debugger listening on ws://127.0.0.1:9229/3126f3b8-3a63-4f83-aa61-615d48701d6b For help, see: https://nodejs.org/en/docs/inspector

projectecho-bookingflow@ dev c:\Users\Gianfranco\Desktop\echo npm run generateLessImport && cross-env NODE_ENV=development node server.js --inspect

Starting inspector on 127.0.0.1:9229 failed: address already in use

According to netstat -abno , vscode is using this process. It might be quite a bear to figure out which extension might be triggering it. Is there a way to set an abritrary port to use in the debug command line, as well as in launch.json ?

– edit: there is: set “port”: 9300 in launch.json, and swap “–inspect” on the node command line to “–inspect=9300”

works for me.

lsof -i :9229

kill -9 PIDNUMBER

I’m having this issue as well. It didn’t occur until updating to VSCode version 1.40.1. When I find the process running on port 9229 and kill it, I get the following message in VSCode:

“Extension host terminated unexpectedly”

Is it possible that extension host is now running on port 9229 as of this version?

https://code.visualstudio.com/api/advanced-topics/extension-host

It’s not a problem with VSCode I think. I am having this issue with nodemon on commandline.

➜  services: export NODE_OPTIONS='--inspect=5445'
➜  services: npx nodemon                         
Debugger listening on ws://127.0.0.1:5445/0ba1c149-b4b3-4aee-9c7e-45f36e98e688
For help, see: https://nodejs.org/en/docs/inspector
[nodemon] 1.19.4
[nodemon] to restart at any time, enter `rs`
[nodemon] watching dir(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `lerna run start`
Starting inspector on 127.0.0.1:5445 failed: address already in use
[nodemon] app crashed - waiting for file changes before starting...

Same issue on 1.40.1. Occurs when debugger attempts to attach to process

I have this issue on 1.41.0-insider
However, I get it after running updates (from 1.40.x-insider) to try and fix it, so it’s a fresh launch and was existent prior as well. Then I run the following from the integrated Powershell terminal yarn start:win The relevant script in package.json being:

"start:win": "set NODE_OPTIONS=\"--inspect\" && yarn verdaccio"

Edit: I think I found the issue. I had launched a docker devcontainer with VSCode, and then my machine crashed. VSCode launched before Docker came up, and that window was reverted to local FS. Docker then came up, and launched the devcontainer, including the crashed debug port, it seems. I found this with TCPView, and it was a quick solve from there. Stopping the container resolved everything.

For anyone else having issues, I recommend checking what’s actually on the port.

what i did are, kill extension host on help -> process list menu, then npm run debug, after that restart extension host. it worked, but really annoy me

I tried to trace code in developer tool. I found that I might be triggered by this line: https://github.com/microsoft/vscode/blob/4934a6f487b9ed6b99b900ae0710c7b452792e20/src/vs/workbench/contrib/extensions/electron-browser/extensionsAutoProfiler.ts#L46

And followed by https://github.com/microsoft/vscode/blob/0f2cda10da1e80088ad7908ac0f743c8f2132de0/src/vs/workbench/services/extensions/common/extensionHostProcessManager.ts#L244

Here is the related change: https://github.com/microsoft/vscode/commit/0f2cda10da1e80088ad7908ac0f743c8f2132de0

Here is the call stack

Just put environment variable flag for debugging in nodemon.json config. For example for next.js users:

"env": {
    "NODE_OPTIONS": "--inspect"
  }

Worked for me without any issues

You can see example config to reference the structure. nodemon.json file should be at project root

@EricJizbaMSFT I’ve commented on the non-nodemon related issue #85328 and explained how we are planning to address this.

ping @jrieken who authored the commit mentioned above and hopefully can help. We’ve had people running into this for Azure Functions scenarios as well. See https://github.com/MicrosoftDocs/azure-docs/issues/42379

cc @fiveisprime @chrisdias

I’m getting this… pretty frustrating. Sometimes I need to restart a couple of times to get it to clear.