Dynamic updates to Avatar result in `derived_inert`

[weston-harper-rox]

Describe the bug

When rendering an avatar component in a dynamic context, such as a client-side navigation or a dynamic list, updating the src attribute will result in a derived_inert warning. A cursory investigation leads to the setTimeout within the onload being the most likely culprit, but more investigation is needed. I was not able to get a breakpoint to fire within the setTimeout teardown function.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-fw2kby1c?file=src%2Froutes%2F%2Bpage.svelte

Logs

client.js:3353 [svelte] derived_inert
Reading a derived belonging to a now-destroyed effect may result in stale values
https://svelte.dev/e/derived_inert
warn	@	client.js:3353
derived_inert	@	chunk-ZNJPOBF7.js?v=c1a8f851:58
execute_derived	@	chunk-6MDOYETR.js?v=c1a8f851:1974
update_derived	@	chunk-6MDOYETR.js?v=c1a8f851:2006
get	@	chunk-6MDOYETR.js?v=c1a8f851:4256
get root	@	bits-ui.js?v=e85682ca:1368
getDocument	@	bits-ui.js?v=e85682ca:1381
getWindow	@	bits-ui.js?v=e85682ca:1384
setTimeout	@	bits-ui.js?v=e85682ca:1404
image.onload	@	bits-ui.js?v=e85682ca:7288

System Info

System:
    OS: macOS 26.4.1
    CPU: (12) arm64 Apple M2 Pro
    Memory: 75.36 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 25.2.1
    npm: 11.6.2
    bun: 1.3.11
  Browsers:
    Safari: 26.4

Severity

annoyance