[Turbopack Nextjs 16]: Pino - Cannot find module './transport-stream'

[CHC383]

Summary: Discussions in this issue have diverged a bit, and there are mainly two cases:

1. Turbopack + non-Vercel deployment. Broken since v16.0.3, maybe due to Turbopack starts to trace worker_threads (fixed [Turbopack Nextjs 16]: Pino - Worker thread cannot find module 'real-require' #84766).
   • Errors (include but not limited to):
     • Parsing ecmascript source code failed (License file) - comment1
     • Can't resolve 'why-is-node-running'/'tap'/etc. (require statement) - comment2, comment3
   • Workaround:
     • Switch back to Webpack. next build --webpack
     • Or add pino, thread-stream and related pino transport target packages to serverExternalPackages, you might also need to add thread-stream as a dependency explicitly.
       • comment4 - Set serverExternalPackages
       • comment5, comment6 - Install thread-stream
       • comment7 - Use shim
       • comment8 - pin to specific versions due to conflicts
2. Turbopack + Vercel deployement. This is the original case of this issue. Turbopack never works in this setup, [Turbopack Nextjs 16]: Pino - Worker thread cannot find module 'real-require' #84766 was fixed in v16.0.3, and now [Turbopack Nextjs 16]: Pino - Cannot find module './transport-stream' #86099 is waiting for a fix. The only workaround is to use Webpack next build --webpack with serverExternalPackages, see Notes below.

Notes:
From comment9

Pino is way too dynamic for Turbopack to be able to figure out all required files automatically: pinojs/pino@7dd79a3/lib/transport.js#L94

Pino itself has a documentation that talks about bundling, and there were already problems since Webpack + Vercel deployment, see comment10.

Also for in−depth details: pinojs/thread-stream#184

---

Link to the code that reproduces this issue

https://github.com/CHC383/nextjs-turbopack-pino-reproduction

To Reproduce

1. Deploy the code to Vercel
2. Visit /api/log
3. Check the log of the Vercel deployment

Current vs. Expected behavior

Current behavior

With Turbopack in NextJs v16, Pino worker thread throws the following error:

Uncaught Exception: Error: Cannot find module './transport-stream'
Require stack:
- /var/task/node_modules/.pnpm/pino@10.1.0/node_modules/pino/lib/worker.js
    at Module._resolveFilename (node:internal/modules/cjs/loader:1383:15)
    at defaultResolveImpl (node:internal/modules/cjs/loader:1025:19)
    at resolveForCJSWithHooks (node:internal/modules/cjs/loader:1030:22)
    at Module._load (node:internal/modules/cjs/loader:1192:37)
    at TracingChannel.traceSync (node:diagnostics_channel:322:14)
    at wrapModuleLoad (node:internal/modules/cjs/loader:237:24)
    at Module.require (node:internal/modules/cjs/loader:1463:12)
    at require (node:internal/modules/helpers:147:16)
    at Object.<anonymous> (/var/task/node_modules/.pnpm/pino@10.1.0/node_modules/pino/lib/worker.js:7:36)
    at Module._compile (node:internal/modules/cjs/loader:1706:14)

Expected behavior

Pino worker thread works without any exception, which is the behavior of using
WebPack.

Provide environment information

Operating System:
  Platform: linux
  Arch: x64
  Version: #84-Ubuntu SMP PREEMPT_DYNAMIC Fri Sep  5 22:36:38 UTC 2025
  Available memory (MB): 15839
  Available CPU cores: 20
Binaries:
  Node: 22.21.1
  npm: 11.6.2
  Yarn: N/A
  pnpm: 10.20.0
Relevant Packages:
  next: 16.0.3 // Latest available version is detected (16.0.3).
  eslint-config-next: N/A
  react: 19.2.0
  react-dom: 19.2.0
  typescript: 5.9.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Turbopack

Which stage(s) are affected? (Select all that apply)

Vercel (Deployed)

Additional context

@mischnic This is a follow up of #84766. It seems that with multiple targets, the pino/lib/worker.js is used and not traced by Turbopack properly. I have updated the reproduction code to trigger the new error.

[soulchild]

We seem to be running into the same issue and it started happening with Next.js 16.0.3. The error looks a bit different though. Dev works fine, but the Turbopack build spits out a very long stacktrace with weird stuff like this:

./node_modules/thread-stream/LICENSE:1:5
Parsing ecmascript source code failed
> 1 | MIT License
    |     ^^^^^^^
  2 |
  3 | Copyright (c) 2021 Matteo Collina
  4 |

Expected ';', '}' or <eof>

Import trace:
  Instrumentation:
    ./node_modules/thread-stream/LICENSE
    ./node_modules/thread-stream/index.js
    ./node_modules/pino/lib/transport.js
    ./node_modules/pino/pino.js
    ./lib/logger.ts
    ./server/services/queue.service.ts
    ./instrumentation.ts

[soulchild]

By the way: Some official way to get structured (JSON) logging with Next.js would be awesome. 😉

[abhijit945]

As a stop-gap solution, marking pacakges with serverExternalPackages seems to work

const nextConfig: NextConfig = {
  serverExternalPackages: ['pino', 'pino-pretty', 'thread-stream'],
};

[mischnic]

I'm afraid that adding pino to serverExternalPackages is the only solution here. Pino is way too dynamic for Turbopack to be able to figure out all required files automatically: https://github.com/pinojs/pino/blob/7dd79a3370f34e0c092dcbc2c6fb1748afcc1cdd/lib/transport.js#L94

But we should probably just add it to the default externals list, so that people don't have to configure it.

[soulchild]

Pino is way too dynamic for Turbopack to be able to figure out all required files automatically. [...] But we should probably just add it to the default externals list, so that people don't have to configure it.

Good idea, but makes me wonder why Pino worked fine up until and including Next.js 16.0.2?

[lesliechueng1996]

If I install the pino from the nextjs app directly, the serverExternalPackages solution is good.
But when I use the nextjs with turborepo and has this dependency list: apps/next-app ---> packages/pino-log ---> pino, the serverExternalPackages solution cannot resolve the issue.

[CHC383]

@mischnic Having pino in the serverExternalPackages list might resolve the error @soulchild encountered, but it doesn't resolve the error I posted, because pino is already in the list (see reproduction code).

pino needs to be in the serverExternalPackages since using Webpack if the application is deployed in the Vercel environment, please see

• https://github.com/pinojs/pino/blob/main/docs/bundling.md
• After building 'unable to determine transport target for "@axiomhq/pino"' due to "cjs" folder being deleted after build pinojs/pino#1964 (comment)

Good idea, but makes me wonder why Pino worked fine up until and including Next.js 16.0.2?

What is the setup you have with 16.0.2 (Turbopack/Webpack, Vercel/Self-hosted, standalone or not, etc.)? One of the changes of Turbopack since 16.0.3 is the fix of #84766.

[soulchild]

What is the setup you have with 16.0.2

• Turbopack
• Self-hosted (Docker/Kubernetes)
• Standalone

[matbour]

I have the same issue, I can point that the issue occurs with v16.0.3 specifically:

• v16.0.1 works
• v16.0.3 crashes with the same error as above
• v16.0.3 with serverExternalPackages works

[jmanywhere]

I tested with the serverExternalPackages stopgap but it breaks.
On my end it's ignoring the exclusion of thread-stream

./node_modules/.pnpm/thread-stream@3.1.0/node_modules/thread-stream/test/helper.js:33:15
Module not found: Can't resolve 'why-is-node-running'
  31 |
  32 | if (process.env.SKIP_PROCESS_EXIT_CHECK !== 'true') {
> 33 |   const why = require('why-is-node-running')
     |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  34 |   setInterval(why, 10000).unref()
  35 | }
  36 |

Currently reverted to using webpack with this config:

webpack: (config) => {
    config.externals.push("pino-pretty", "lokijs", "encoding");
    return config;
  },