privileges don't work with grant all privileges

create user test identified by 'test';

Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> grant all privileges on *.* to test;

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

I am 'root@localhost', and if I restart the server with skip-grant-tables, I cannot assign privileges. I need to assign all privileges to a user because for backup I need to dump the mysql.user table, and this fails without full privileges, I mean, if you try then you get nothing, mariadb-dump cannot dump that critical table. So I am in a circle. Is there a solution to this nightmare?