Works only if there is only one Svelte component in the project

[thojanssens]

I added in App.svelte :

<svelte:options tag="svelte-clock" />

<script>
  import Hello from './Hello.svelte';
  /* code */

I added a file Hello.svelte, and just wrote in the file:

hello!

But now when running npm run build, the following error message is shown:

src/main.js → public/build/bundle.js...
(!) Plugin svelte: No custom element 'tag' option was specified. To automatically register a custom element, specify a name with a hyphen in it, e.g. <svelte:options tag="my-thing"/>. To hide this warning, use
<svelte:options tag={null}/>
src\Hello.svelte
1: hello!
^
2:
created public/build/bundle.js in 685ms