problem description

create the component with vue-cli 3, publish it to npm, and quote the Times error:
Failed to mount component: template or render function not defined.

related codes

hellocomp.js

export default {
  name: "HelloComp",

  render(h) {
    return (
      <div class="h-comp">
        Hello from Component
      </div>
    )
  }
}

index.js

import HelloComp from "./hellocomp.js"

HelloComp.install = function(Vue, options = {}) {
  Vue.component(HelloComp.name, HelloComp)
}

if (typeof window !== "undefined" && window.Vue) {
  Vue.component(HelloComp.name, HelloComp)
}

export default HelloComp

webpack.config.js

module.exports = {
  entry: "./src/index.js",
  ...

then npm publish,
reference Test.vue in the project

<template>
    <div>
      <hello-comp />
    </div>
</template>

import HelloComp from "hello-comp"

@Component({
  components: {
    HelloComp 
  }
})
export default class Test extends Vue {
  ...

after starting, you see the following error in console

[Vue warn]: Failed to mount component: template or render function not defined.

exactly what went wrong?
if it is not published to npm, it is normal to put it directly in the project