Create slots inside slot-block error

[likemusic]

<!-- TestBase.vue -->
<template>
  <div>
    <h1>Base Component</h2>
    <div>
      <slot name="body">Component body</slot>
    </div>
  </div>
</template>
...

<!-- TestChild component -->
<slot name="body">
  <div>
      <span>Overrided body content</span>
      <slot name="form">Your form content</slot>
  </div>
</slot>
 
<script>
export default {
    extends: TestBase
}
</script> 

<!-- TestSubChild component -->
<slot name="form">
  <div>SubChild form content</div>
</slot>
 
<script>
export default {
    extends: TestChild
}
</script> 

This thows an error:

vue.common.dev.js?4650:630 [Vue warn]: Error in created hook: "TypeError: Cannot read property 'bind' of undefined"

found in

---> <TestSubChild> at resources/js/Domain/Test/TestSubChild.vue
       <Root>

[likemusic]

I found many other issues with current implementation.

For my requirements I made some fixes in fork's inheritable-branch. Maybe it will help someone.

[likemusic]

As result of my investigation, I think it would be better to implement this package functionality by injecting slots in template-code. But I'm not sure that this is really possible.

[likemusic]

After many fixes and debugging I have created my own loader - vue-template-extends - that implemented by setting render functions for component options ( render and staticRenderFns) (because template-option is not respected in SFC).