Statement.getWarnings() is null (sometimes) although there are errors

org.mariadb.jdbc.Statement.getWarnings() is null in the case below:

CREATE OR REPLACE PACKAGE `test`.`employee_tools` AS

  FUNCTION getSalary(eid INT) RETURN DEXIMAL(10,2);

END

Expected a warning. This is used to determine where in the statement things went wrong. The exception also does not seem to contain any information about where the error happened:

e = {SQLException@14683} "java.sql.SQLException: (conn=13) Unknown data type: 'DEXIMAL'"

 SQLState = "HY000"

 vendorCode = 4161