Svelte 5: "Cannot use fallback values with bind"

[NotSpaulding]

Describe the bug

When trying to use default values for component props and binding them to a variable when using the component it throws an error. This looks intended but it is very annoying and unnecessary, requiring the user to create hacky fixes for a very simple task.

Reproduction

Svelte 5 (error)
Svelte 5 (hacky fix)
Svelte 4 (example of how you'd implement this in Svelte 4)

Logs

No response

System Info

npmPackages:
  svelte: 5.0.0-next.37 => 5.0.0-next.37

Severity

annoyance

[JLAcostaEC]

Same here, I'm using svelte 5.0.0-next.42

[7nik]

It was intentionally introduced in #9764

[dummdidumm]

This no longer throws when the binding has a value - which should be easy to do in the parent -, therefore closing.