In a regular Master-Slave configuration the Slave sql erros out a dup key.
The slave has been set up via backup restore and is claimed not to have
any local updates. The backup restore procedure is standard to include
`set global gtid_slave_pos=$GTID_from_backup` where the gtid value is
extracted from `xtrabackup_info`. Barring a mistake of the slave gtid state setting,
``change master to master_host='xx.xx.xxx', master_port=zzzz master_user='user', master_password='xxxxx', master_use_gtid=slave_pos;
should've worked out without any issue.
However the slave stopped. More details can be found on the customer issue page.