Calling clean_term_cache() fails when called in the same plugin that creates terms, succeeds when called separately?

My plugin code is below. In the myPlugin_cleanup() function, I’m creating some categories and assigning term id 1 as the parent.

Due to the known bug with creating categories via script (the category_children array does not get created and results in a fatal error when pages containing category listings are accessed), I’ve placed the clean_term_cache() call directly below the function that creates my categories.

However, its not working. The category_children option is not getting created.

Interestingly, if I create a plugin whose sole function is to execute the clean_term_cache(”,’category’) call, it fixes the problem and creates the category_children option with the correct values.

I’m just not sure why its not working in the same plugin that creates the categories.

What might I be missing?

function myPlugin_activate(){
    if ( get_option( 'myPlugin_activated' ) !== "1"){
        //comment out any function you don't want to run
        myPlugin_copy('themes');
        myPlugin_copy('plugins');
        myPlugin_images();
        myPlugin_options();
        myPlugin_settings();
        myPlugin_widgets();
        myPlugin_links();
        myPlugin_posts();
        myPlugin_pages();
        myPlugin_custom_menus();
        myPlugin_cleanup();
        clean_term_cache('','category'); //does not work here
        update_option('myPlugin_activated', "1");
        }
    }

function myPlugin_cleanup(){

        //include dependencies
        require_once(ABSPATH.'/wp-admin/includes/taxonomy.php');    

        if(!get_cat_ID('nofollow')){wp_create_category('nofollow',1);}
        if(!get_cat_ID('noindex')){wp_create_category('noindex',1);}

        clean_term_cache('','category'); //Does not appear to work here either.
        }


register_activation_hook(__FILE__, 'myPlugin_activate');
?>

After creating about 40 test WP installs today on localhost, here’s what I can report:

It appears that the correct function call to rebuild the category_children options is:

_get_term_hierarchy('category')

Previously, I was trying to call:

clean_term_cache('','category')

And I was calling it just after my categories were created in my plugin code. However, I could never get this function to do anything when called from the same plugin that I’m using to create the categories. Interestingly, I could place the function in a stand-alone plugin and run it (after my category creation plugin) and it would rebuild the category_parents options array perfectly.

The reason it can’t be called in the same script that creates the categories appears to be related to a peculiar behavior of clean_term_cache() which is best stated by “foofy” in a comment in the bug track ticket:

This is only a problem if you make
multiple term changes in the same PHP
request/script lifetime.
clean_term_cache() tracks each
taxonomy it cleans in a static
variable and won’t clean it a second
time. If several term changes are made
in the same request, the
{$taxonomy}_children option is left
with the hierarchy as it was after the
first change.

I hope this helps someone!