Cannot find package "cookie" error on running in production

[nickw1]

Hi @lazarv (or others)

I'm getting a hard-to-diagnose error most of the time when I run my project

https://github.com/nickw1/lilt

Steps:

in production mode. Running in dev mode is fine, and build is fine, but when trying to start I get this error (node 22.14.0, Linux):

$ pnpm react-server start 
Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'cookie' imported from /home/nick/src/lilt/.react-server/server/src/components/AdminComponent.DQeUMsjE.mjs
Did you mean to import "cookie/dist/index.js"?
    at Object.getPackageJSONURL (node:internal/modules/package_json_reader:268:9)
    at packageResolve (node:internal/modules/esm/resolve:768:81)
    at moduleResolve (node:internal/modules/esm/resolve:854:18)
    at defaultResolve (node:internal/modules/esm/resolve:984:11)
    at nextResolve (node:internal/modules/esm/hooks:748:28)
    at resolve (file:///home/nick/src/lilt/node_modules/.pnpm/@[email protected]_@[email protected]_ac_4b729a96d3b022b288ab9e7f7d8503a5/node_modules/@lazarv/react-server/lib/loader/node-loader.react-server.mjs:11:16)
    at nextResolve (node:internal/modules/esm/hooks:748:28)
    at Hooks.resolve (node:internal/modules/esm/hooks:240:30)
    at handleMessage (node:internal/modules/esm/worker:199:24)
    at Immediate.checkForMessages [as _onImmediate] (node:internal/modules/esm/worker:141:28) {
  code: 'ERR_MODULE_NOT_FOUND'
}

With the latest 20250827 version this appears as a command-line error while with the earlier 20250803 version it's a runtime error instead when accessing the index page.

Steps:

git clone https://github.com/nickw1/lilt
pnpm i
pnpm react-server build
pnpm react-server start

npm doesn't have this error. The "marking as external" fix for cookie doesn't seem to fix the issue.
I note that two versions of cookie are being used, not sure if this is the issue?

I tried reproducing it with a simpler example (the session example from the repo, I chose this as cookie is a dependency of iron-session) but the error did not occur so unfortunately it looks hard to diagnose, but just posting here in the Q&A in case you have any ideas.

It's not critical as I can use npm instead if need be, but just wondering if there was a way to get it to work with pnpm.

Thanks.

[lazarv]

Hi @nickw1!

When a similar error happens, you can use pnpm why with the package name of the missing dependency to check what is using the dependency that was not found, and mark that dependency as external. In this case, iron-session. You need to mark the highest-level dependency as external, as only these are resolvable directly for your application when using pnpm. You can also solve this by installing the missing dependency.

The modified vite.config.mjs that works:

import { defineConfig } from "vite";

export default defineConfig({
  // base: '/lilt/', // uncomment if you have a non-default base dir e.g. https://hikar.org/lilt
  port: 3002,
  resolve: { external: ["iron-session"] },
});

I also removed the @vitejs/plugin-react as the framework is now using rolldown-vite and the Oxc-based React plugin by default, which is much faster than the Babel-based plugin.

[nickw1]

Hi @lazarv, many thanks for the advice! Very helpful.