[Custom Components] Blocked when using dynamic children for rendering

[Col0ring]

Describe the bug

In gradio 6.9.0, when using dynamic children for rendering, the following error appears in the console and fails to render (the same code works in gradio 6.8.0).

The svelte code:

<script lang="ts">
  import { Gradio } from '@gradio/utils'

  const props = $props()
  // Read props to clean up the loading effect
  new Gradio(props)

  const promise = new Promise<string>((resolve) => {
    setTimeout(() => {
      resolve('hello')
    }, 500)
  })
</script>

{#await promise then value}
  <div>
    {value}
    <!-- not working -->
    {@render props.children?.()}
  </div>
{/await}

<!-- worked -->
<!-- {@render props.children?.()} -->

Have you searched existing issues? 🔎

• I have searched and found no existing issues

Reproduction

Reproduction repo: https://github.com/Col0ring/gradio6.9-dynamic-children-rendering-issue

Screenshot

No response

Logs

System Info

gradio version: 6.9.0
gradio_client version: 2.3.0

Severity

Blocking usage of gradio

[pngwn]

Yeah this is a known issue due to some recent changes and svelte limitations. I’m hoping we can fix this more generally at some point in the future, but no eta as of yet.

[Col0ring]

Yeah this is a known issue due to some recent changes and svelte limitations. I’m hoping we can fix this more generally at some point in the future, but no eta as of yet.

Thanks for your reply. Does this mean I can only use these components by switching to Gradio 6.8.0 for the time being?

[pngwn]

Yeah, I think so. Will try to get this fixed ASAP but the constraints are tricky.

[freddyaboulton]

Hi @Col0ring ! We've really appreciated all the issues you've opened and suggestions you've made to custom components over the last years. We'd love to ask for your feedback on custom components and Gradio as a whole. What works, what doesn't, what changes you'd like to see made, and to learn how you use Gradio.

If you're interested in giving your feedback please email us at gradio-team@huggingface.co and we can go from there. Thank you 🙏 🤗

[Col0ring]

Thank you for the invitation! I'll give it a try.