fix(dev): warn when the bundled dev runtime and the installed rolldown version mismatch

packages/vite/rolldown.config.ts

@@ -4,6 +4,7 @@ import { ImportType, init, parse } from 'es-module-lexer'
 import MagicString from 'magic-string'
 import type { Plugin } from 'rolldown'
 import { defineConfig } from 'rolldown'
+import rolldownPkg from 'rolldown/package.json' with { type: 'json' }
 import pkg from './package.json' with { type: 'json' }
 import licensePlugin from './rollupLicensePlugin'
 
@@ -83,6 +84,11 @@ const nodeConfig = defineConfig({
     cli: path.resolve(dirname, 'src/node/cli.ts'),
     internal: path.resolve(dirname, 'src/node/internalIndex.ts'),
   },
+  transform: {
+    define: {
+      __VITE_BUNDLED_ROLLDOWN_VERSION__: JSON.stringify(rolldownPkg.version),
+    },
+  },
   external: [
     /^vite\//,
     'fsevents',

packages/vite/src/client/bundledDevClient.ts

@@ -13,6 +13,10 @@ import {
   updateStyle,
 } from './client'
 
+// Replaced with the rolldown version this client was built against when the
+// file is served, see `getHmrImplementation` in `node/plugins/clientInjections.ts`.
+declare const __VITE_BUNDLED_ROLLDOWN_VERSION__: string
+
 // keep the same public exports as `client.ts`, which this entry replaces when inlined
 export {
   createHotContext,
@@ -51,6 +55,8 @@ if (typeof DevRuntime !== 'undefined') {
   const runtime = ((globalThis as any).__rolldown_runtime__ ??=
     new ViteDevRuntime(clientId))
 
+  ;(runtime as any).bundledRolldownVersion = __VITE_BUNDLED_ROLLDOWN_VERSION__
+
   const bundledDevHmrClient = new BundledDevHMRClient(
     {
       error: (err) => console.error('[vite]', err),

packages/vite/src/node/constants.ts

@@ -35,6 +35,12 @@ export const ROLLUP_HOOKS: RollupPluginHooks[] = [
 
 export const VERSION = version as string
 
+declare const __VITE_BUNDLED_ROLLDOWN_VERSION__: string
+export const BUNDLED_ROLLDOWN_VERSION: string | undefined =
+  typeof __VITE_BUNDLED_ROLLDOWN_VERSION__ === 'undefined'
+    ? undefined
+    : __VITE_BUNDLED_ROLLDOWN_VERSION__
+
 const DEFAULT_MAIN_FIELDS = [
   'browser',
   'module',

packages/vite/src/node/plugins/clientInjections.ts

@@ -2,7 +2,12 @@ import fs from 'node:fs'
 import path from 'node:path'
 import { cleanUrl } from '../../shared/utils'
 import type { ResolvedConfig } from '../config'
-import { CLIENT_ENTRY, ENV_ENTRY, BUNDLED_DEV_CLIENT_ENTRY } from '../constants'
+import {
+  CLIENT_ENTRY,
+  ENV_ENTRY,
+  BUNDLED_DEV_CLIENT_ENTRY,
+  BUNDLED_ROLLDOWN_VERSION,
+} from '../constants'
 import { perEnvironmentState } from '../environment'
 import type { Plugin } from '../plugin'
 import { isObject, normalizePath, resolveHostname } from '../utils'
@@ -120,6 +125,9 @@ async function createClientConfigValueReplacer(
   const serverForwardConsoleReplacement = escapeReplacement(
     config.server.forwardConsole as any,
   )
+  const bundledRolldownVersionReplacement = escapeReplacement(
+    BUNDLED_ROLLDOWN_VERSION ?? 'unknown',
+  )
 
   return (code) =>
     code
@@ -136,6 +144,10 @@ async function createClientConfigValueReplacer(
       .replace(`__HMR_CONFIG_NAME__`, hmrConfigNameReplacement)
       .replace(`__WS_TOKEN__`, wsTokenReplacement)
       .replace(`__SERVER_FORWARD_CONSOLE__`, serverForwardConsoleReplacement)
+      .replace(
+        /__VITE_BUNDLED_ROLLDOWN_VERSION__/g,
+        bundledRolldownVersionReplacement,
+      )
 }
 
 export async function getHmrImplementation(

packages/vite/src/node/server/bundledDev.ts

@@ -7,8 +7,12 @@ import {
   type DevEngine,
   dev,
 } from 'rolldown/experimental'
+import rolldownPkg from 'rolldown/package.json' with { type: 'json' }
 import { ChunkMetadataMap, resolveRolldownOptions } from '../build'
-import { BUNDLED_DEV_CLIENT_FILENAME } from '../constants'
+import {
+  BUNDLED_DEV_CLIENT_FILENAME,
+  BUNDLED_ROLLDOWN_VERSION,
+} from '../constants'
 import { getHmrImplementation } from '../plugins/clientInjections'
 import { createDebugger, formatAndTruncateFileList } from '../utils'
 import { convertToDevWatchOptions } from '../watch'
@@ -116,6 +120,7 @@ export class BundledDev {
 
   async listen(): Promise<void> {
     this._closed = false
+    checkBundledRolldownVersion(this.environment)
     debug?.('INITIAL: setup bundle options')
     const rolldownOptions = await this.getRolldownOptions()
     // NOTE: only single outputOptions is supported here
@@ -561,3 +566,22 @@ function debounce(time: number, cb: () => void) {
 function payloadDeliveredAck(filename: string): string {
   return `\n;__rolldown_runtime__.payloadDelivered(${JSON.stringify(filename)});`
 }
+
+function checkBundledRolldownVersion(environment: DevEnvironment): void {
+  // undefined when running from source, where nothing is pre-bundled
+  if (BUNDLED_ROLLDOWN_VERSION === undefined) return
+  const installed = rolldownPkg.version
+  if (installed === BUNDLED_ROLLDOWN_VERSION) return
+  environment.logger.warn(
+    colors.yellow(
+      `experimental.bundledDev: this Vite release bundles the rolldown dev runtime ` +
+        `of rolldown@${BUNDLED_ROLLDOWN_VERSION}, but the installed rolldown@${installed} ` +
+        `generates the code that runtime executes. The mismatch can break dynamic ` +
+        `imports or HMR at runtime with errors like ` +
+        `"__rolldown_runtime__.requestLazy is not a function".\n` +
+        `To fix this, upgrade Vite to a release built against rolldown@${installed}, ` +
+        `or pin rolldown to ${BUNDLED_ROLLDOWN_VERSION} (e.g. via the "overrides" ` +
+        `field in package.json).`,
+    ),
+  )
+}