Runes mode: Binding in each loop not working

[ralphdelfs]

Describe the bug

In runes mode, when iterating an array of objects in an each loop, it is not possible to bind the object to a component.

<svelte:options runes={true} />
<script>
	import Component from "./Component.svelte"
	
	let objs = [{
		val: "foo"
	}]
</script>

{#each objs as obj}
  <Component bind:obj />
{/each}

Error each_item_invalid_assignment is raised. This works fine when runes mode is disabled.

Reproduction

https://svelte.dev/playground/71e6da2a2afd4a5e812bdd7263e5c7dd?version=5.12.0

Logs

Cannot reassign or bind to each block argument in runes mode. Use the array and index variables instead (e.g. `array[i] = value` instead of `entry = value`)
https://svelte.dev/e/each_item_invalid_assignment

System Info

svelte 5.12.0, see repl

Severity

blocking an upgrade

[Prinzhorn]

This comes up regularly, maybe the error message should be better? the error message tells you exactly what to do.

Use the array and index variables instead (e.g. array[i] = value instead of entry = value)

You need to use the index: https://svelte.dev/playground/3d2230fb0247489dafb27f995901b1a6?version=5.12.0

Edit: still, the error message is a little poorly worded and does not look like a binding, it should be:

(e.g. bind:value={array[i] instead of bind:value={entry})