<?php

ini_set('display_errors', 1);
header("Content-Type: text/plain; charset=utf-8");
error_reporting(E_ALL);

$counter = 0;

// срабатывает при ошибке
set_error_handler(function ($errno, $errstr, $errfile, $errline) use (&$counter) {
    echo "\n\n\nCounter=$counter\n";
    throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
});

for ($counter = 0; $counter < 10000; $counter++) {
    echo $counter % 10;
    setcookie('test', '12345', time() - 1);
}

echo "END";