Для wordpress 5 трассировка вызова:
#0 ptrace() called at [/wp-includes/class-wp-query.php:1571]
#1 WP_Query->set_404() called at [/wp-includes/class-wp.php:697]
#2 WP->handle_404() called at [/wp-includes/class-wp.php:718]
#3 WP->main() called at [/wp-includes/functions.php:964]
#4 wp() called at [/wp-blog-header.php:16]
#5 require(wp-blog-header.php) called at [/var/www/zaharochek/index.php:20]
Трасса из файла wp-includes/class-wp-query.php метод: