Same here! Getting Uncaught TypeError: Vue__default.default.extend is not a function here:

Here's the line:

Any news? @alfonsobries

Any news?

I have solved this issue by installing yarn add @vitejs/plugin-vue2 and adding it in vite.config.js:

 // vite.config.js
import vue from '@vitejs/plugin-vue2'

export default {
  plugins: [vue()]
}

https://github.com/vitejs/vite-plugin-vue2

Bit hacky, isn't it?

Sure, but it worked for me as a quick fix for now. Of course, for vue v.2.7.x.

I have solved this issue by installing yarn add @vitejs/plugin-vue2 and adding it in vite.config.js:

This is what I was expecting to work, but I am still getting the same issue where extend is not a function

I had this problem and I solved it by adding a plugin to my Vite config that modifies the vue-tailwind code:

Here's the plugin

const modifyVueTailwind = {
    name: 'modifyVueTailwind',
    transform(code, id) {
        if (!/vue-tailwind\/dist\/(vue-tailwind|components)\.js/.test(id)) {
            return
        }

        return code.replace(
            "function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }",
            "function _interopDefaultLegacy (e) { return e && (typeof e === 'object' || typeof e === 'function' ) && 'default' in e ? e : { 'default': e }; }",
        )
    }
}

And then within my plugins array within defineConfig:

plugins: [
    vue(),
    modifyVueTailwind,
    // additional plugins ... 
]

You may need to modify the regex in the transform function based on how you're importing the tailwind library.