Broken Aria References

At Drupal South code sprint. As far as I know this still needs tests and fixes for the pages mentioned in the issue summary.
Added IS template to help others but it still needs to be completed,

Just running into this issue in a custom theme. Here is the code sample that generates the «Broken ARIA reference» error:

<!-- BEGIN OUTPUT from 'core/modules/system/templates/input.html.twig' -->
<input data-drupal-selector="edit-subscriptions-sip-n-savour" aria-describedby="edit-subscriptions--description" type="checkbox" id="edit-subscriptions-sip-n-savour" name="subscriptions[sip_n_savour]" value="sip_n_savour" class="form-checkbox">
<!-- END OUTPUT from 'core/modules/system/templates/input.html.twig' -->

<!-- BEGIN OUTPUT from 'core/modules/system/templates/form-element-label.html.twig' -->
<label for="edit-subscriptions-sip-n-savour" class="option">SIP n’ SAVOUR</label>

For the short term, simply adding an ID to the checkbox label does the job; the use case is Simplenews subscriptions on user register page.

/**
 * Implements template_preprocess_form_element_label().
 */
function my_custom_theme_preprocess_form_element_label(&$variables) {
  $id = $variables['element']['#id'] ?? '';
  if ($id && str_contains($id, 'edit-subscriptions-')) {
    $variables['attributes']['id'] = 'edit-subscriptions--description';
  }
}