Meituan-Dianping/mpvue · error

option "${key}" can only be used during instance creation wi

Error message

option "${key}" can only be used during instance creation with the `new` keyword.

What it means

Comes from the el/propsData option merge strategies in dev mode. These strategies receive the vm argument during mergeOptions; when vm is absent the merge is happening for a component definition (Vue.extend / component registration) rather than instance creation, and el/propsData are per-instance options that only make sense with 'new Vue(...)'. Declaring them on a component definition triggers this warning; the value is then merged with the default strategy but is ignored when the definition is used as a component.

Source

Thrown at src/core/util/options.js:35

  capitalize,
  isBuiltInTag,
  isPlainObject
} from 'shared/util'

/**
 * Option overwriting strategies are functions that handle
 * how to merge a parent option value and a child option
 * value into the final value.
 */
const strats = config.optionMergeStrategies

/**
 * Options with restrictions
 */
if (process.env.NODE_ENV !== 'production') {
  strats.el = strats.propsData = function (parent, child, vm, key) {
    if (!vm) {
      warn(
        `option "${key}" can only be used during instance ` +
        'creation with the `new` keyword.'
      )
    }
    return defaultStrat(parent, child)
  }
}

/**
 * Helper that recursively merges two data objects together.
 */
function mergeData (to: Object, from: ?Object): Object {
  if (!from) return to
  let key, toVal, fromVal
  const keys = Object.keys(from)
  for (let i = 0; i < keys.length; i++) {
    key = keys[i]
    toVal = to[key]

View on GitHub (pinned to 6c5d78ee04)

Solutions

1. Remove el/propsData from the component definition; pass them at instantiation: new Vue({ el: '#app', propsData })
2. Supply mount targets via the $mount API or the el on the root instance only
3. For props in tests, pass them through the mounting utility (e.g. propsData in vue-test-utils mount options) rather than the component options

When it happens

Trigger: Thrown at src/core/util/options.js:35 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Meituan-Dianping/mpvue@6c5d78ee04 (2026-09-02). Data as JSON: /api/errors/aa741137bdd68526. Report an issue: GitHub.