[Bug] Build error when slotting a component into another with `webc:setup` script

I was trying to create a reusable <select> component, and my naive approach was to use slots, but that didn't work. I've resorted to using a render function within my custom select WebC component and it works now. However, to be generic, I'm trying to pass data in as an object and dynamically render it on the other side. The reproduction and the workaround I've found are at the bottom of this issue.

Bug

<!-- Main component -->
<script webc:setup>
  function options() {
    return [
      "1",
      "2",
      "3",
      "4",
    ];
  }
</script>

<cr-fieldset>
  <cr-select
    name="motivation" 
    :@options="options()"
  ></cr-select>
</cr-fieldset>

<!-- cr-fieldset -->
<fieldset :data-required="required">
  <legend>
    <h2 @text="title"></h2>
    <p @text="label"></p> 
  </legend>
  <slot></slot>
</fieldset>

<!-- cr-select -->
<select
  :name="name"
>
  <option value="">Please select</option>
  <script webc:type="js" webc:root>
    options
      .map((value) => `<option value="${value}">${value}</option>`)
      .join("\n");
  </script>
</select>

This results in the follow error:

Reproduction

Reproduction commit: https://github.com/darthmall/webc-select-options-setup-func-repro/pull/1/commits/247df02bac1e017f935bdbde5f94cc61d7b66cee

I managed to get around the issue by pulling the setup script and <cr-select> to a separate file.

Workaround commit: https://github.com/darthmall/webc-select-options-setup-func-repro/pull/1/commits/df8ef9be1dcc2e94d8a84abcf89713e1b77b538a

Start with the reproduction commit linked in the issue and run its build to observe the error involving webc:setup, slots, and cr-select. Compare it with the workaround commit to identify the relevant compiler path; done means the original inline setup and slotted component build successfully without requiring separate files.