Version

3.2.8

Reproduction link

github.com

Steps to reproduce

1. npm install
2. npm run dev
3. the console will print:

Uncaught TypeError: Cannot read property 'call' of undefined
    at hasOwn (shared.esm-bundler.js:492)
    at Array.doSet (runtime-core.esm-bundler.js:5210)
    at flushPostFlushCbs (runtime-core.esm-bundler.js:7193)
    at render2 (runtime-core.esm-bundler.js:5144)
    at mount (runtime-core.esm-bundler.js:3479)
    at Object.app.mount (runtime-dom.esm-bundler.js:1515)
    at main.js:4

What is expected?

no error

What is actually happening?

print TypeError: Cannot read property 'call' of undefined.

Fix and explanation of issue supplied here. https://github.com/vuejs/vue-next/pull/4515