`nuxi dev --inspect` incorrect behavior (impossible to inspect nitro-runtime, server functions, middlewares and so on)

[Irelynx]

Environment

---

• Operating System: Windows_NT
• Node Version: v22.3.0
• Nuxt Version: 3.12.3
• CLI Version: 3.12.0
• Nitro Version: 2.9.7
• Package Manager: pnpm@9.3.0
• Builder: -
• User Config: debug, compatibilityDate, devtools
• Runtime Modules: -
• Build Modules: -

---

Reproduction

• Create new nuxt project (nuxi create test)
• add file: server/api/test.get.ts

  export default defineEventHandler(async (event) => {
    console.log('request!');
    debugger;
    return { ok: true };
  });

• enable debug messages in nuxt.config.ts

  // https://nuxt.com/docs/api/configuration/nuxt-config
  export default defineNuxtConfig({
    debug: true,
    compatibilityDate: '2024-04-03',
    devtools: { enabled: true }
  })

• run in dev mode with --inspect flag (nuxi dev --inspect)
• open Chrome DevTools and connect to process
• when nuxt finish warming up, do the following HTTP request: GET /api/test (res = await fetch('/api/test', { method: 'GET' }))
• check console - you will see the logs
• check DevTools - you will NOT see any logs after [nitro] dev:reload, debugger keyword will not trigger debugging as well. Sources tab doesn't contain any project files (except some dependencies from node_modules)
  

Describe the bug

The bug is inability to inspect/debug what is going on inside server-side functions (endpoints), middlewares, pages rendering (debugger keyword in pages/components/composables/...).

Additional context

Possible reference: #21312 (i didn't find solution there)

Logs

(please see attached screenshot in Reproduction section)

[darrenweb]

I have the same problem, Is there a solution now?

[marc-arnoult]

Same issue here, impossible to debug performance / memory leak without that.

No problem with the IDE configuration, unfortunately it's not enough.

[ayalon]

The problem is, that the debugger is attached to the CLI file which does not include source map for your project.
I did not found a solution yet how to attach debugger to the real child process.

[ilnytskyi]

Same issue here, in vscode debugging seem to work fine, even --experimental-network-inspection sees the request fired from the server.

But in Chrome devtools it sees only nuxt.mjs and some deps in node_modules. Also network requests not picked up.
Parent process only sees nuxt.config.ts file and requests to child process. But according to ps there is only two nuxt processes, so it's unclear how to make inspectable nuxt dev mode.

Also tried to attach to both process via kill -USR1 pid but no success, child process just refuses to be debuggable with Chrome.

Maybe it's something related to forking, like passing correct cwd or other options.

Production builds work fine as there is only one process.