The problem seems to be with restoring original 'plugin' value in the 'mysql.user' table by executing
update mysql.user set plugin='';
This statement relies on the fact that at the beginning of the test the value of the 'plugin' field was also an empty string. This is not true, at least for 5.6.30, where this value is originally 'mysql_native_password'.
The problem seems to be with restoring original 'plugin' value in the 'mysql.user' table by executing
update mysql.user set plugin='';
This statement relies on the fact that at the beginning of the test the value of the 'plugin' field was also an empty string. This is not true, at least for 5.6.30, where this value is originally 'mysql_ native_ password' .