Using `$inspect` rune with remote functions causes internal error in the build

[sukeshpabolu]

Describe the bug

Using $inspect rune with remote functions in a page is causing internal error when the build is run.

Reproduction

Enable experimental async and remoteFunctions

import adapter from '@sveltejs/adapter-node';

/** @type {import('@sveltejs/kit').Config} */
const config = {
	kit: {
		adapter: adapter(),
		experimental: {
			remoteFunctions: true
		}
	},
	compilerOptions: {
		sourcemap: process.env.NODE_ENV === 'development',
		experimental: {
			async: true
		}
	}
};

export default config;

Create a remote function

//$lib/remote/items.remote.js

import { query } from '$app/server';

export const getItem = query(() => {
	return {
		x: "Hello World"
	}
});

Create +page.svelte file

<script lang="ts">
    //./src/routes/items/+page.svelte
	import { getItem } from '$lib/remote/items.remote.js';

	const item = $derived(await getItem());
	let a = $state(5);
    //comment below line if the build has to work properly
	$inspect(a);
</script>

<br />

<button onclick={() => {a++}}>
	incr
</button>
<br />
{item.x}
<br />
{a}

• Run pnpm build
• Run pnpm preview
• Try to open http://localhost:4173/items in browser
• Reproducable repo: sukeshpabolu/remote-inspect-bug-app

Logs

[500] GET /items
TypeError: fn is not a function
    at file:///C:/Users/sukeshp/Documents/remote-inspect-bug-app/.svelte-kit/output/server/chunks/index.js:747:18
    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
    at async Promise.all (index 0)

System Info

System:
    OS: Windows 10 10.0.19045
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i5-1145G7 @ 2.60GHz
    Memory: 3.11 GB / 15.73 GB
  Binaries:
    Node: 22.21.1 - C:\Users\sukeshp\nodejs\node.EXE
    npm: 10.9.4 - C:\Users\sukeshp\nodejs\npm.CMD
    pnpm: 10.28.0 - C:\Users\sukeshp\AppData\Local\pnpm\pnpm.CMD
    bun: 1.3.5 - C:\Users\sukeshp\.bun\bin\bun.EXE
    Deno: 2.5.4 - C:\Users\sukeshp\.deno\bin\deno.EXE
  Browsers:
    Edge: Chromium (143.0.3650.80)
    Firefox: 133.0.3 - C:\Program Files\Mozilla Firefox\firefox.exe
    Internet Explorer: 11.0.19041.5794
  npmPackages:
    @sveltejs/adapter-node: ^5.5.1 => 5.5.1
    @sveltejs/kit: ^2.50.0 => 2.50.0
    @sveltejs/vite-plugin-svelte: ^6.2.4 => 6.2.4
    svelte: ^5.48.0 => 5.48.0
    vite: ^7.3.1 => 7.3.1

Severity

annoyance

Additional Information

No response

[teemingc]

Similar to #17406 looks like it’s not fully fixed