Bug of local transition with keyed clause

[micaste]

Is this about svelte@next? This project is currently in a pre-release stage and breaking changes may occur at any time. Please do not post any kind of bug reports or questions on GitHub about it.

No

Describe the bug
When using the {#key } clause, the local transitions do not work well.

To Reproduce

https://svelte.dev/repl/f20a688175914fb2a0f5ff45a75360b5?version=3.32.1

Expected behavior
In the provided REPL, the expected behavior is for the items to enter and exit in a smooth manner, with or without local modifier. It only happens with the keyed clause, and works well with an {#each } clause: https://svelte.dev/repl/b0c3bafb93a6463d81e846d30f80f5ba?version=3.32.1

Information about your Svelte project:

The REPL uses Svelte 3.32.1. Reproduced on Safari 14.0.2 and Chrome 88 on OSX 11.1

Severity
It prevents me from using local transitions in an image carousel: https://strollyn.com/explore . I'd like the transition not to run when mounting or changing page.
Some workarounds are possible (using scroll for the carrousel maybe), but the severity is not that large

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ruvkr]

Also having this issue: https://svelte.dev/repl/33f123d7c2c24b37b8fc580219de1ead?version=3.38.3

[andrevvm]

Having this issue as well: https://svelte.dev/repl/c5b0e5731caf4531bfb024f828a6c344?version=3.38.3

[dennisjlee]

I'm facing this same issue (also in trying to create a carousel). It seems to me that the |local modifier for transitions should also apply if the element is being rendered due to an immediate parent {#key} re-rendering.

[7nik]

My test case https://svelte.dev/repl/9ade56926d33497980edd41af6597c70?version=3.44.2
and if you need a workaround, use

{#each [key] as k(k)}
  your code
{/each}

instead of #key block

[Valexr]

in:blur={{duration:1000, delay: 1000}} out:blur={{duration:1000}}

[Conduitry]

This should be fixed in 3.48.0 - https://svelte.dev/repl/f20a688175914fb2a0f5ff45a75360b5?version=3.48.0