If your MySQL database is misconfigured, you will see error messages such as:

ER_WRONG_FIELD_WITH_GROUP

...which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by...

To fix

Openmy.cnf (sudo find / -name my.cnf) and remove only_full_group_by from sql_mode.

For a full list of CLI error messages read the Ghost-CLI guide.