If you try to start() Madelineproto in a closure instead of regular file you'll get a startup exception in Magic.php:255
self::$script_cwd = self::$cwd = \dirname(end($backtrace)['file']);

because closures don't have "file" value in returned debug_backtrace() array but in "function":

Array
(
    [0] => Array
        (
            [function] => {closure:/app/test.php:35}
            [args] => Array
                (
                )
        )
)

Furthermore, these two lines in the same file should be removed as well:

            set_error_handler(Exception::exceptionErrorHandler(...));
            set_exception_handler(Exception::exceptionHandler(...));

It is very bad practice and anti-pattern to modify exception handling routines inside the library if it's not strictly required by library itself.