vitejs/vite · error · AggregateError

oxc transform error

Error message

oxc transform error

What it means

AggregateError thrown while scanning entries: oxc's synchronous transform (`transformSync`) is applied to a non-JS file (e.g. TS/JSX) before running glob-import rewriting, and the transform emitted one or more errors. scan.ts:431 wraps them with the message 'oxc transform error'. It indicates the source could not be transpiled by oxc during dependency discovery.

Solutions

1. Upgrade Vite (which bundles oxc) to pick up newer syntax support.
2. Simplify or fix the syntax in the offending entry file; locate it via the AggregateError's inner errors.
3. Review `optimizeDeps.rolldownOptions.transform` jsx settings; remove overrides that conflict.
4. Exclude the problematic entry from scanning via `optimizeDeps.entries` or by excluding the dep.
5. If a dependency ships unsupported syntax, pre-build it or pin a compatible version.

Example fix

// before: optimizeDeps.transform forces jsx preset that breaks the file
export default defineConfig({
  optimizeDeps: { rolldownOptions: { transform: { jsx: 'react' } } },
})

// after
export default defineConfig({
  optimizeDeps: { rolldownOptions: { transform: { jsx: { runtime: 'automatic' } } } },
})

import { transformSync } from 'oxc-parser'
import fs from 'node:fs'

function assertOxcTransformable(file: string, lang: 'jsx' | 'tsx' | 'ts') {
  const res = transformSync(file, fs.readFileSync(file, 'utf8'), { lang, tsconfig: false })
  if (res.errors.length) throw new Error(`${file} fails oxc transform: ${res.errors[0].message}`)
}
// run over TS/JSX entries during a prebuild

try {
  await server.listen()
} catch (e) {
  if (e instanceof AggregateError && e.message === 'oxc transform error') {
    const detail = (e.errors ?? []).map((er: any) => er.message).join('; ')
    console.error('oxc transform failed during scan:', detail)
  }
  throw e
}

When it happens

Trigger: In `doTransformGlobImport` (scan.ts:417), when `loader !== 'js'`, `transformSync(id, contents, { jsx: jsxOptions, lang: loader, tsconfig: false })` runs. If `result.errors.length > 0`, the AggregateError is thrown. Occurs for .ts/.tsx/.jsx entries that contain syntax oxc rejects under the configured jsx/lang options.

Common situations: TypeScript/JSX syntax newer than the bundled oxc version supports. Decorators, satisfies operator, or other syntax not enabled. Custom jsx options (`optimizeDeps.rolldownOptions.transform.jsx`) that conflict with the file. Malformed source. Version skew between Vite and the oxc binary.

Related errors

• oxc transform error
• Unable to parse: .
• Could not resolve " " imported by " ". Is it installed?
• Failed to load `transformWithEsbuild`. It is deprecated and…
• failed to resolve rolldownOptions.input value

AI-assisted analysis of vitejs/vite@b4d66fee14 (2026-08-11). Data as JSON: /api/errors/39ae53d343233a86. Report an issue: GitHub.

Appendix: source

Thrown at packages/vite/src/node/optimizer/scan.ts:431

    id: path,
    external: !entries.includes(path),
  })

  const doTransformGlobImport = async (
    contents: string,
    id: string,
    loader: Loader,
  ) => {
    let transpiledContents: string
    // transpile because `transformGlobImport` only expects js
    if (loader !== 'js') {
      const result = transformSync(id, contents, {
        ...(jsxOptions !== undefined ? { jsx: jsxOptions } : {}),
        lang: loader,
        tsconfig: false,
      })
      if (result.errors.length > 0) {
        throw new AggregateError(result.errors, 'oxc transform error')
      }
      transpiledContents = result.code
    } else {
      transpiledContents = contents
    }

    const result = await transformGlobImport(
      transpiledContents,
      id,
      environment.config.root,
      resolve,
    )

    return result?.s.toString() || transpiledContents
  }

  const scripts: Record<
    string,

View on GitHub (pinned to b4d66fee14)