Storybook globals don't exist in `rolldown-vite`-based build

[bengry]

Describe the bug

When using rolldown-vite with Storybook v10 and @storybook/addon-docs, the built Storybook fails at runtime with ReferenceError: __STORYBOOK_MODULE_*__ is not defined.

What I expect: Built Storybook loads without errors, same as with standard Vite.

What actually happens: Console errors on page load:

Uncaught ReferenceError: __STORYBOOK_MODULE_CORE_EVENTS_PREVIEW_ERRORS__ is not defined
    at csf-BrJoaeT2.js:4:13387

or

Uncaught ReferenceError: __STORYBOOK_MODULE_CLIENT_LOGGER__ is not defined
    at instrumenter-LwmSDSR-.js:48:53

Observations:

• Only affects built Storybook (dev mode works fine)
• Only happens when @storybook/addon-docs is enabled (other addons work fine). Might not be related to this addon speicifically, since another smaller repo with it works, but I guess it happens in some cases due to chunking/code splitting.
• Standard Vite does NOT have this issue - only rolldown-vite
• I noticed a csf-*.js chunk (~149KB) appears in rolldown-vite builds but not in standard Vite builds - this might be related to differences in code splitting behavior

Reproduction

https://github.com/bengry/rolldown-vite-storybook-globals-bug

Steps to reproduce

1. Clone the repo and install:

   git clone https://github.com/bengry/rolldown-vite-storybook-globals-bug
   cd rolldown-vite-storybook-globals-bug
   yarn install

2. Build Storybook:

   yarn build-storybook

3. Serve the built output:

   npx serve ./apps/storybook/storybook-static

4. Open browser and check devtools console - you'll see the ReferenceError

System Info

System:
  OS: macOS 26.1
  CPU: (16) arm64 Apple M3 Max
  Memory: 494.23 MB / 64.00 GB
  Shell: 4.2.1 - /opt/homebrew/bin/fish
Binaries:
  Node: 24.10.0
  Yarn: 4.12.0
  npm: 11.7.0
Browsers:
  Chrome: 143.0.7499.110
  Safari: 26.1
npmPackages:
  @vitejs/plugin-react: ^5.1.2 => 5.1.2 
  rolldown-vite: 7.2.11

Used Package Manager

yarn

Logs

Click to expand!

# Build output shows csf chunk:
storybook-static/assets/csf-BrJoaeT2.js   149.02 kB │ gzip: 46.82 kB

# Browser console error:
Uncaught ReferenceError: __STORYBOOK_MODULE_CORE_EVENTS_PREVIEW_ERRORS__ is not defined
    at csf-BrJoaeT2.js:4:13387

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• 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.

[sapphi-red]

Storybook uses a custom module loader in the bundle, which heavily relies on the module execution order. Keeping the module execution order correct while reducing the number of chunks & the code size is a difficult problem, and Rolldown does not keep it in some cases (related document). Rolldown has experimental.strictExecutionOrder option that can preserve the execution order with the cost of output size. If you add that to apps/storybook/.storybook/main.ts, the output would work.

import type { StorybookConfig } from "@storybook/react-vite";

const config: StorybookConfig = {
  // other options
  async viteFinal(config, { configType }) {
    config.build ??= {}
    config.build.rolldownOptions ??= {};
    config.build.rolldownOptions.experimental = {
      strictExecutionOrder: true,
    };
    return config;
  },
};

export default config;

If storybook can use importmaps instead of a custom module loader, I guess this option won't be needed.

[bengry]

Storybook uses a custom module loader in the bundle, which heavily relies on the module execution order. Keeping the module execution order correct while reducing the number of chunks & the code size is a difficult problem, and Rolldown does not keep it in some cases (related document). Rolldown has experimental.strictExecutionOrder option that can preserve the execution order with the cost of output size. If you add that to apps/storybook/.storybook/main.ts, the output would work.

import type { StorybookConfig } from "@storybook/react-vite";

const config: StorybookConfig = {
// other options
async viteFinal(config, { configType }) {
config.build ??= {}
config.build.rolldownOptions ??= {};
config.build.rolldownOptions.experimental = {
strictExecutionOrder: true,
};
return config;
},
};

export default config;
If storybook can use importmaps instead of a custom module loader, I guess this option won't be needed.

Thanks! That worked.
IIUC, this is an underlying issue with how Storybook's build system works with Vite, and so ideally they'd fix it in their builder's end (and not with this experimental flag you suggested). Do you have any further details I can provide them so I can open an issue in https://github.com/storybookjs/storybook? I guess more people would face this once Vite 8 is released.

[sapphi-red]

There're some information here: #182 (comment)