vuejs/vue · critical · Error

Your JavaScript runtime does not support any asynchronous pr

Error message

Your JavaScript runtime does not support any asynchronous primitives that are required by vue-server-renderer. Please use a polyfill for either Promise or setTimeout.

What it means

Thrown at module-load time by write.ts when the defer primitive cannot be resolved. defer is chosen from process.nextTick, then Promise.resolve().then, then setTimeout; if all are undefined, defer falls back to noop and the guard throws. vue-server-renderer relies on deferring render continuation to avoid stack overflows (MAX_STACK_DEPTH = 800), so without an async primitive it cannot function. This is an environment-compatibility error.

Source

Thrown at packages/server-renderer/src/write.ts:14

const MAX_STACK_DEPTH = 800
const noop = _ => _

const defer =
  typeof process !== 'undefined' && process.nextTick
    ? process.nextTick
    : typeof Promise !== 'undefined'
    ? fn => Promise.resolve().then(fn)
    : typeof setTimeout !== 'undefined'
    ? setTimeout
    : noop

if (defer === noop) {
  throw new Error(
    'Your JavaScript runtime does not support any asynchronous primitives ' +
      'that are required by vue-server-renderer. Please use a polyfill for ' +
      'either Promise or setTimeout.'
  )
}

export function createWriteFunction(
  write: (text: string, next: Function) => boolean,
  onError: Function
): Function {
  let stackDepth = 0
  const cachedWrite = (text, next) => {
    if (text && cachedWrite.caching) {
      cachedWrite.cacheBuffer[cachedWrite.cacheBuffer.length - 1] += text
    }
    const waitForNext = write(text, next)
    if (waitForNext !== true) {
      if (stackDepth >= MAX_STACK_DEPTH) {

View on GitHub (pinned to 9e88707940)

Solutions

Polyfill at least one: global.Promise = require('es6-promise').Promise or global.setTimeout = ... before requiring vue-server-renderer.
Run in a standard Node.js environment (all three primitives are native).
If in a custom embedding, expose nextTick/setTimeout/Promise on the global scope before loading the module.
Avoid stripping globals in security sandboxes; instead run SSR in an isolated but complete Node process.

Example fix

// before — runtime lacks async primitives, require throws
const VueSSR = require('vue-server-renderer')

// after — polyfill before require
global.Promise = global.Promise || require('core-js-pure/features/promise')
global.setTimeout = global.setTimeout || require('timers').setTimeout
const VueSSR = require('vue-server-renderer')

Defensive patterns

Strategy: fallback

Validate before calling

function assertAsyncPrimitivesAvailable(): void {
  const has =
    (typeof process !== 'undefined' && typeof process.nextTick === 'function') ||
    typeof Promise === 'function' ||
    typeof setTimeout === 'function'
  if (!has) {
    throw new Error(
      'Environment lacks process.nextTick, Promise, and setTimeout. Polyfill at least one before loading vue-server-renderer.'
    )
  }
}

assertAsyncPrimitivesAvailable()
require('vue-server-renderer')

Type guard

function environmentSupportsAsync(): boolean {
  return (
    (typeof process !== 'undefined' && typeof process.nextTick === 'function') ||
    typeof Promise === 'function' ||
    typeof setTimeout === 'function'
  )
}

Try / catch

// Thrown at module-load (require) time — wrap the require in try/catch:
let VueSSR
try {
  VueSSR = require('vue-server-renderer')
} catch (e) {
  if (e.message.includes('does not support any asynchronous primitives')) {
    global.Promise = global.Promise || require('core-js-pure/features/promise')
    VueSSR = require('vue-server-renderer')
  } else {
    throw e
  }
}

Prevention

Run SSR in a standard Node.js environment which has all three async primitives natively.
Before loading vue-server-renderer in custom runtimes, polyfill Promise or setTimeout on the global scope.
Do not strip globals in security sandboxes; isolate via process instead.
Add an environment smoke test in CI that requires vue-server-renderer and catches load-time errors.

When it happens

Trigger: Loading vue-server-renderer in a JavaScript runtime that has none of: process.nextTick, native Promise, setTimeout. This is exotic — most Node and browser environments have at least one. Seen in stripped-down JS engines, some edge-case Nashorn/JVM JS runtimes, or environments where these globals were deleted/polyfill-blocked.

Common situations: Running SSR in a constrained sandbox that removes global timers/Promise for security. A JS engine embedded in a non-browser/non-Node host (e.g. a database stored-procedure JS engine) without async primitives. A bundler/misconfigured environment that tree-shook or stubbed out Promise/setTimeout.

Understand the failure class

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

AI-assisted analysis of vuejs/vue@9e88707940 (2026-08-11). Data as JSON: /api/errors/a3ab123f2af50030. Report an issue: GitHub.