Can't build example in tutorial

[d47081]

$ composer exec zephir build

[ERROR] Extension namespace cannot be loaded
Script zephir handling the __exec_command event returned with error code 1

Source

# utils/utils/greeting.zep
namespace Utils;

class Greeting
{

    public static function say()
    {
        echo "hello world!";
    }

}

Installed by composer require phalcon/zephir

• Composer 2.5.5
• PHP 8.2
• Debian 12