[vite]: Rollup failed to resolve import "react-redux"

[ThePeach]

Hello all, I'm a bit stuck so I wanted to see if anyone can help me a bit.

I have just completed the upgrade of vite from v5 to v6.
I am working in a monorepo, with React v18 (and other react-related deps).
Each package has it's own vite.config.js file which looks pretty much like this:

import path from 'path';
import { defineConfig, loadEnv } from 'vite';
import react from '@vitejs/plugin-react';

import packageJson from './package.json';

const DEFAULT_PORT = 9001;

// https://vitejs.dev/config/
export default defineConfig(({ mode }) => {
  const env = loadEnv(mode, process.cwd());
  const dontOpenBrowser = env.VITE_BROWSER === 'none';

  return {
    build: {
      lib: {
        entry: packageJson.main,
        name: path.basename(__dirname),
        fileName: 'index',
        formats: ['esm'],
      },
      minify: true,
      rollupOptions: {
        input: packageJson.main,
        output: {},
      },
      sourcemap: mode !== 'production',
    },
    envDir: '../../',
    plugins: [react()],
    server: {
      port: DEFAULT_PORT
    },
  };
});

This config was working fine in the previous version, so it might be I missed something in the upgrade.

Consider also that one of the changes during the upgrade was to move Vite as a dependency in the monorepo root, and remove it from each package. I have not found anyone suggesting this shouldn't be done, but just want to be explicit, just in case.

Lastly, the error:
When running vite build --mode test
I get:

vite v6.3.5 building for test...
transforming...
✓ 22 modules transformed.
error during build:
[vite]: Rollup failed to resolve import "react-redux" from "/app/packages/b/src/main.jsx".
This is most likely unintended because it can break your application at runtime.
If you do want to externalize this module explicitly add it to
`build.rollupOptions.external`
    at viteLog (file:///app/node_modules/vite/dist/node/chunks/dep-DBxKXgDP.js:46345:15)
    at file:///app/node_modules/vite/dist/node/chunks/dep-DBxKXgDP.js:46403:18
    at onwarn (/app/node_modules/@vitejs/plugin-react/dist/index.cjs:120:9)
    at file:///app/node_modules/vite/dist/node/chunks/dep-DBxKXgDP.js:46401:7
    at onRollupLog (file:///app/node_modules/vite/dist/node/chunks/dep-DBxKXgDP.js:46393:5)
    at onLog (file:///app/node_modules/vite/dist/node/chunks/dep-DBxKXgDP.js:46043:7)
    at file:///app/node_modules/rollup/dist/es/shared/node-entry.js:20784:32
    at Object.logger [as onLog] (file:///app/node_modules/rollup/dist/es/shared/node-entry.js:22664:9)
    at ModuleLoader.handleInvalidResolvedId (file:///app/node_modules/rollup/dist/es/shared/node-entry.js:21410:26)
    at file:///app/node_modules/rollup/dist/es/shared/node-entry.js:21368:26
npm error Lifecycle script `build:test` failed with error:
npm error code 1
 npm error path /app/packages/a
npm error workspace @getolo/a@1.0.0
npm error location /app/packages/a
npm error command failed
npm error command sh -c vite build --mode test

as you can probably imagine, package/a is importing package/b. package/b is one of the packages that is importing react-redux, amongst others.

In package/a/vite.config.js I have added to the rollupOptions the following:

        external: ['react-redux', '@reduxjs/toolkit'],

(@reduxjs/toolkit was also another issue that was brought up after I added react-redux, so added them both).
I have not added the external variable in the vite.config.js in package/b.

This should be it, isn't it? Now the application builds fine...

BUT

When loading my application I get this error which breaks everything:
Uncaught TypeError: Failed to resolve module specifier "react-redux". Relative references must start with either "/", "./", or "../".

Suggestions? Am I missing anything?

[yanglee2421]

Same issue here. It seems to only occur on Windows. #20293

[ThePeach]

I managed to get around this specific issue by adding

    optimizeDeps: {
      include: ['react-redux', '@redux/toolkit'],
    },

to the vite.config.js file. Now I'm stuck on another problem.