Why does cron accept a simple PHP script, but not a little more complicated one?

Question

PHP

Tell me why cron perceives a simple PHP script, but a little more complicated - no?

crontab -e:

* * * * * php /var/www/project/includes/mail/cron.php

Accepts and works:

$to = '...';
    $subject = 'Its test msg';
    $message = 'Cron. You login: ';
    $from = "From: [email protected]\r\n"
        ."Content-type: text/html; charset=utf-8\r\n"
        ."X-Mailer: PHP mail script";

    mail(
        $to,
        $subject,
        $message,
        $from
    );

It does not perceive, but if you go through a direct link - it works:

require '../model.php';
$allUsers = R::findAll('users');

foreach ($allUsers as $user)
{
    $to = $user->login;
    $subject = 'Its test msg';
    $message = 'Cron. You login: '.$user->login.' ';
    $from = "From: [email protected]\r\n"
        ."Content-type: text/html; charset=utf-8\r\n"
        ."X-Mailer: PHP mail script";

    mail(
        $to,
        $subject,
        $message,
        $from
    );
}

upd. Logs in the script:

Answer 1

Read the logs. For example, there are no users in the database. Or there are too many of them and there is not enough memory. Execute your script yourself through the console, turning on error output. The problem is in the script, not in the cron.