lean/skeleton/public/index.php

<?php

try {
    require_once(dirname(__DIR__)."/src/Kernel.php");
}
catch(\Throwable $t) {
    echo sprintf("%s in <strong>%s</strong> <pre>%s</pre>", $t->getMessage(), $t->getFile() . ":" . $t->getLine(), $t->getTraceAsString());
}