Svelte 5: [commonjs--resolver] No known conditions for "./elements" specifier in "svelte" package

[yangfuhai]

Describe the bug

Button.svelte:

<script lang="ts">

    import type { HTMLButtonAttributes } from 'svelte/elements';

    const { ...rest }: HTMLButtonAttributes = $props();
</script>
<button type="button" {...rest} class="tf-btn nopan nodrag {rest.class}">
    <slot></slot>
</button>

svelte.config.js

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

export default {
    // Consult https://svelte.dev/docs#compile-time-svelte-preprocess
    // for more information about preprocessors
    preprocess: [
        vitePreprocess({
            script: true
        })
    ],
    compilerOptions: {
        // accessors: true,
        customElement: true
    }
};

vite.config.ts

import { defineConfig } from 'vite';
import { resolve } from 'path';
import { svelte } from '@sveltejs/vite-plugin-svelte';
import dts from 'vite-plugin-dts';

// https://vitejs.dev/config/
export default defineConfig({
    build: {
        outDir: 'dist',
        emptyOutDir: true,
        minify: true,
        sourcemap: false,
        lib: {
            entry: resolve(__dirname, 'src/index.ts'),
            // formats: ['es'],
            name: 'Tinyflow',
            fileName: 'tinyflow'
        }
    },
    plugins: [svelte({ emitCss: false }), dts({
        rollupTypes: true ,
        // tsconfigPath: './tsconfig.app.json'
    })],

});

then execute npm run build will result in an error: [commonjs--resolver] No known conditions for "./elements" specifier in "svelte" package。

Reproduction

git clone https://github.com/tinyflow-ai/tinyflow
pnpm install
pnpm run build

Logs

System Info

System:
    OS: macOS 15.1.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
    Memory: 8.97 GB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.10.0 - /usr/local/bin/node
    Yarn: 1.22.22 - /usr/local/bin/yarn
    npm: 10.9.1 - /usr/local/bin/npm
    pnpm: 8.15.6 - ~/Library/pnpm/pnpm
  Browsers:
    Chrome: 133.0.6943.127
    Safari: 18.1.1
  npmPackages:
    svelte: ^5.20.2 => 5.20.2

Severity

blocking all usage of svelte

[yangfuhai]

If you modify Button.svelte to the following code, this problem will not occur.

<script lang="ts">
    const { ...rest }: any = $props();
</script>
<button type="button" {...rest} class="tf-btn nopan nodrag {rest.class}">
    <slot></slot>
</button>

[Ocean-OS]

The svelte/elements is just a type declaration module, so when compiled, it converts the import to import "svelte/elements", but since there's no actual code to import, an error happens. Related #15236

[yangfuhai]

The svelte/elements is just a type declaration module, so when compiled, it converts the import to import "svelte/elements", but since there's no actual code to import, an error happens. Related #15236

The related issue did not provide any solution。

[dummdidumm]

#15236 (comment) this is the solution. Search your code for a missing import type