create role developer;

grant select,insert,update,delete on *.* to developer;

grant usage on *.* to `user01`@`%` identified by 'user01';

grant developer to `user01`@`%`;

flush privileges;

MariaDB [mysql]> select host, user, is_role from mysql.user;

+-----------+-----------+---------+

| host      | user      | is_role |

+-----------+-----------+---------+

| localhost | root      | N       |

| 127.0.0.1 | root      | N       |

| %         | user01    | N       |

|           | developer | Y       |

+-----------+-----------+---------+

4 rows in set (0.01 sec)

MariaDB [mysql]> select * from roles_mapping;

+-----------+--------+-----------+--------------+

| Host      | User   | Role      | Admin_option |

+-----------+--------+-----------+--------------+

| %         | user01 | developer | N            |

+-----------+--------+-----------+--------------+

1 rows in set (0.01 sec)

MariaDB [(none)]> select current_user, current_role;

+--------------+--------------+

| current_user | current_role |

+--------------+--------------+

| user01@%     | NULL         |

+--------------+--------------+

1 row in set (0.01 sec)

MariaDB [(none)]> set role developer;

ERROR 1959 (OP000): Invalid role specification `developer`.