Drupal allowed_values_function does not get called when creating a field - drupal-7

Question

For some reason my allowed_values_function never gets called when showing a field on a user bundle. Code:
function get_business_units()
{
$options = entity_load('business_unit', FALSE, NULL, FALSE);
$opt = bu_to_list_values($options);
return $opt;
}
function MYMODULE_enable()
{
if (!field_info_field('field_user_business_unit')) {
$field = array(
'field_name' => 'field_user_business_unit',
'type' => 'text',
'settings' => array(
'allowed_values' => array(),
'allowed_values_function' => 'get_business_units',
)
);
field_create_field($field);
// Create the instance on the bundle.
$instance = array(
'field_name' => 'field_user_business_unit',
'entity_type' => 'user',
'label' => 'Business Unit',
'bundle' => 'user',
'required' => FALSE,
'settings' => array(
'user_register_form' => 1,
),
'widget' => array(
'type' => 'options_select',
),
);
field_create_instance($instance);
}
}
The field is created, and even displayed on the users "edit" page when editing their info. But the only value is "Select" or "None". My method is never called (I even placed a debug point). This is all in MYMODULE.install file.

Answer 1

The problem is: 'type' => 'text'.
You have to use: 'type' => 'list_text'.
Allowed values is meaningless for a text type.

Answer 2

Your get_business_units() function needs to be in the MYMODULE.module file; the .install files aren't included in a normal Drupal bootstrap.

Answer 3

Have you tried
drush features-revert MYMODULE ?