Svelte 5: Strange store behavior

[PatrickG]

Describe the bug

I've encountered this bug in a Sveltekit + Svelte 5 app.

Reproduction

The reproduction might be a bit confusing. I mimicked Sveltekit because otherwise I was not able to reproduce the bug.

Reproduction

Click the "Change page prop" button multiple times.
The test state in Layout.svelte stays true even tho the same expression in the $inspect rune does evaluate to false which you can see in the console.

Some strange things:

• If you modify line 16 in App.svelte to be { a: 4, b: 'X' } - which leads to test being true when initialized - test is changing correctly (true -> false -> true -> etc.). But if you remove line 16 in Layout.svelte, line 14 will only rerender once.
• If you modify the derived expression in Layout.svelte from $page.a === 4 || $page.b === 'Y' to $page.a === 4 (so test is still false when initialized), test is changing correctly as well. But still, if you remove line 16, line 14 will only rerender once.

Logs

No response

System Info

Svelte 5

Severity

blocking all usage of svelte

[trueadm]

This seems to work for me now?

[PatrickG]

This seems to work for me now?

Yea, it works now. Thank you ❤️
Which PR fixed it? (I guess #10111)