`optimized dependencies changed. reloading` log appears on every startup with `@vitejs/plugin-react`

[hi-ogawa]

Describe the bug

I'm not sure since when, but I just noticed rolldown-vite logs this for every startup.

$ pnpm -C packages/plugin-rsc/examples/starter dev 

> @vitejs/plugin-rsc-examples-starter@0.0.0 dev /home/hiroshi/code/others/vite-plugin-react/packages/plugin-rsc/examples/starter
> vite

2:02:27 PM [vite] (client) Re-optimizing dependencies because vite config has changed

  ROLLDOWN-VITE v7.1.0  ready in 149 ms

  ➜  Local:   http://localhost:5173/
  ➜  Network: use --host to expose
  ➜  press h + enter to show help
2:02:27 PM [vite] (client) ✨ optimized dependencies changed. reloading

It's possible this might be the cause of Waku CI failure https://github.com/vitejs/vite-ecosystem-ci/actions/runs/17634518373/job/50450596715 (I tested locally and the same log shows up on Waku too) and also recent rsc plugin CI flakiness vitejs/vite-plugin-react#854

I can also look into it, but it would be great if you have a hunch why this might be.

Reproduction

https://github.com/vitejs/vite-plugin-react

Steps to reproduce

On stackblitz https://stackblitz.com/edit/github-txe9huiu?file=package.json

Or locally

• clone https://github.com/vitejs/vite-plugin-react
• add overrides: vite: npm:rolldown-vite@latest in pnpm-workspace.yaml
• run pnpm build
• run pnpm -C packages/plugin-rsc/examples/starter dev

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 20.19.1 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    @vitejs/plugin-react: latest => 5.0.2 
    @vitejs/plugin-rsc: latest => 0.4.30 
    rolldown-vite:  7.1.10

Used Package Manager

pnpm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs and the Rolldown-related guide.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

It turned out this can be reproduced with @vitejs/plugin-react https://stackblitz.com/edit/vitejs-vite-v2qbf8uy?file=vite.config.ts It looks like config hash used for optimization caching isn't stable

rolldown-vite/packages/vite/src/node/optimizer/index.ts

Line 1243 in db8a886

function getConfigHash(environment: Environment): string {

I dumped hash content and let Claude code check the hashing diff and it says this:

● Looking at the full config path differences:

  Initial config (Lines 5, 6, 8, 9, 22, 23, 25, 26):
  {
    "optimizeDeps": {
      "rollupOptions": {
        "transform": {
          "jsx": {
            "runtime": "automatic"
          }
        }
      }
    }
  }

  Changed config (Lines 16, 33):
  {
    "optimizeDeps": {
      "rollupOptions": {
        "transform": {
          "jsx": {
            "runtime": "automatic",
            "development": true
          },
          "typescript": {
            "onlyRemoveTypeImports": true,
            "removeClassFieldsWithoutInitializer": false
          },
          "assumptions": {
            "setPublicClassFields": false
          }
        }
      }
    }
  }

  The changes occur at these paths:
  - optimizeDeps.rollupOptions.transform.jsx.development - newly added
  - optimizeDeps.rollupOptions.transform.typescript - newly added object
  - optimizeDeps.rollupOptions.transform.assumptions - newly added object

  These transform options are dynamically added by the OXC plugin after initial startup, causing the config hash to change and triggering the "Re-optimizing dependencies because vite config has changed"
   message.