SYS_CONNECT_BY_PATH results longer than 8000 characters can lead to error

The function SYS_CONNECT_BY_PATH can lead to an error under rare conditions.
A precondition for this problem is that the result of SYS_CONNECT_BY_PATH exceeds 8000 characters.
Example:

create table t(x int);
insert into t values 0,0;
select sys_connect_by_path(x, '_OOOOOOOO_')
    from t 
    connect by 
        prior x = x
        and level < 35;