Problem with hook_packages_before

Hi,

Is it normal to have the hook “hook_packages_before” inside tpl-add.php and add-table.php.

Because when I try this:

function jjjjj_hook_packages () {
	echo "hello";
	}
add_action('hook_packages_before', 'jjjjj_hook_packages');

It display on the page like that: hello hello

But, if I delete the line 17 in add-table.php
hook_packages_before();

The display on the page is correct: hello

Did someone know a better solution, please ?