TypeError: key(): Argument #1 ($array) must be of type array, string given in key()

Per #6

I faced the similar issue, posted here, https://www.drupal.org/project/drupal/issues/3477465 🐛 TypeError: key(): Argument #1 ($array) must be of type array, null given in key() (line 368 of /public_html/web/core/modules/user/src/AccountForm.php) Active
I checked with new Drupal 10 dump with a image field added into user entity, the issue does not persist there.

But For my existing site, I literally uninstalled all custom modules and most of the contributed modules, but still getting issue. So dump the $form_state->getValues() there and see if "roles" values are there, but its not. I got this:

Array
(
    ....
    [3] => field_test_picture
    ....
    [20] => field_user_other_website
    [21] => field_user_picture
    [23] => field_user_state
    [24] => field_user_twitter
    [25] => field_user_youtube
    .....
    [26] => path
    [27] => user_picture
    [28] => submit
    [29] => form_build_id
    [30] => form_token
    [31] => form_id
    [32] => contact
    [33] => field_test_picture_0_upload_button
    [34] => mail
    [35] => pass
    [36] => field_parent_account

As it mentioned in the AccountForm.php, this process is called twice:

  /**
   * {@inheritdoc}
   */
  public function buildEntity(array $form, FormStateInterface $form_state) {
    // Change the roles array to a list of enabled roles.
    // @todo Alter the form state as the form values are directly extracted and
    //   set on the field, which throws an exception as the list requires
    //   numeric keys. Allow to override this per field. As this function is
    //   called twice, we have to prevent it from getting the array keys twice.

I debugged, in the first call "roles" key is there. But in the second call, "roles" is absent.

Take a different approach to check if roles is empty. MR12855 and patch file attached.
Updated steps to reproduce.

Think we need steps that don’t involve a contrib module. Also may have to do some more backtracking as putting just an empty() check could be masking a larger issue