Svelte 5: $inspect() causes infinite loop

[mjadobson]

Describe the bug

Adding $inspect(..) to otherwise working code causes an infinite loop.

This doesn't seem to occur when using $effect(() => console.log(..))

Reproduction

https://svelte-5-preview.vercel.app/#H4sIAAAAAAAAE31TwY6cMAz9FSsdCVARdNsbMCP12EtPvS2rKsuY2WyDgxLTboX49yoJhZnVtgeEHPs9x-85s-iVRieq-1mQHFBU4vM4ilzw79EH7idqRpELZybb-ZPGdVaNfGqpZTWMxjJckL8wDg56awZIilL5qHh2SX1V9cvKcavwQRHJtzr_aWTQalAMRzg4lozpXXaTDdxwDHRpmsHxtPVPAzLLaoCWfH0_UcfKECjqLA5InGYwBzaOXd4f4S7QLxFRlvDVgDZmLIrCHxyw77HjtVNnyBmNhTaXNA7ZTdYicZZt-G9PygUGt1KUJRwUudHT3IJ8Z2rKXVFqHidmQ2Co06r7cZy3my9B8XDrCubwXzw4Ak4tNUaHkvkdyu4JbjqBdOFgibM3Wp1mHxeML7w0pVYRWnpooDX6JHIxmLPqFZ5FxXbCJd-W5Mq_fVme3fWibOIHp3palfceniXL3eDd31uxV6PW4p7SrIZg1aq1RZ4s_S27IMM67W7yVuRJYpvgNC91S8FyfAnLecZeTjouaf2_wYOs_xrZr8e-ofdB0u_qXEFyl-Tgta4gkeOoMVnyq-zHPfsoSZK8TX_a08ZKumCytPRQv3H9TfNXTwJmiMOvcsTlcFp1mH7I44vzNixvzP6w_AFjRACMJQQAAA==

Logs

No response

System Info

svelte@5.0.0-next.120

Severity

annoyance

[paoloricciuti]

Can I ask you why the weird wrap contraption instead of using $derived or $derived.by? With that it doesn't loop infinitely

[mjadobson]

Can I ask you why the weird wrap contraption instead of using $derived or $derived.by? With that it doesn't loop infinitely

It's a minimal repro for the bug report. I noticed the bug when looking at a REPL on the discord. It used a wrapping function to capture signals used in an async/subscribed data query.

[Rich-Harris]

Simpler repro here. Haven't got to the bottom of it yet