Latest build breaks svelte completely

[Zhoros]

Describe the bug

I have tested with older version of svelte 3.0.x and it worked fine,
The latest version as of today, 5.27.0, is not working, I have observed this issue in previous 5.20.0 as well

I created my project with vite, it seems to be an issue with the compiler itself more than anything.

package.json

{
  "name": "vite-project",
  "private": true,
  "version": "0.0.0",
  "type": "module",
  "scripts": {
    "start": "vite build --watch"
  },
  "devDependencies": {
    "@sveltejs/vite-plugin-svelte": "^5.0.3",
    "svelte": "^5.27.0",
    "vite": "^6.2.0"
  }
}

vite.config.js (This should be irrelavant, but just gonna put it here)

import { defineConfig } from 'vite'
import { svelte } from '@sveltejs/vite-plugin-svelte'

// https://vitejs.dev/config/
export default defineConfig({

	root: './src',
	base: './',
	server: {
		watch: {
			usePolling: true,
			interval: 250,
		}
	},
	plugins: [svelte()],
	build: {

		rollupOptions: {
			
			input: {
				
				page: './src/page.html',

			},

		},

		outDir: '../../public/authorized/s',
		assetsDir: '',
		emptyOutDir: true,

	}

})

page.svelte

<script>

</script>

<main>

	<span>test</span>
	
</main>

resulting page-B20UA30j.js

(function(){const n=document.createElement("link").relList;if(n&&n.supports&&n.supports("modulepreload"))return;for(const e of document.querySelectorAll('link[rel="modulepreload"]'))o(e);new MutationObserver(e=>{for(const r of e)if(r.type==="childList")for(const s of r.addedNodes)s.tagName==="LINK"&&s.rel==="modulepreload"&&o(s)}).observe(document,{childList:!0,subtree:!0});function i(e){const r={};return e.integrity&&(r.integrity=e.integrity),e.referrerPolicy&&(r.referrerPolicy=e.referrerPolicy),e.crossOrigin==="use-credentials"?r.credentials="include":e.crossOrigin==="anonymous"?r.credentials="omit":r.credentials="same-origin",r}function o(e){if(e.ep)return;e.ep=!0;const r=i(e);fetch(e.href,r)}})();const f="5";var c;typeof window<"u"&&((c=window.__svelte??(window.__svelte={})).v??(c.v=new Set)).add(f);const a=2;var u,d;function l(t){return d.call(t)}let m=null;function p(t){var n=document.createElement("template");return n.innerHTML=t,n.content}function _(t,n){var i=m;i.nodes_start===null&&(i.nodes_start=t,i.nodes_end=n)}function g(t,n){var i=(n&a)!==0,o,e=!t.startsWith("<!>");return()=>{o===void 0&&(o=p(e?t:"<!>"+t),o=l(o));var r=i||u?document.importNode(o,!0):o.cloneNode(!0);return _(r,r),r}}function v(t,n){t!==null&&t.before(n)}var y=g("<main><span>test</span></main>");function h(t){var n=y();v(t,n)}new h({target:document.getElementById("app")});

Reproduction

Logs

above

System Info

on windows 11, using node v22 LTS. Tested on microsoft edge

Severity

can't use at all

[Zhoros]

Svelte 5 uses mount() function, I had to modify my .js file.