I am also wondering about compatibility with Sugar V 8.0. One of our clients has already been thru the health check for V 8.0 upgrade and gotten this error. It may be a PHP version issue. Any additional info much appreciated!
This process failed due to the following file and/or incompatible integrations:
[2018-05-03T01:49:16+00:00] BUCKET => F: [Issue 79][phpError][E_WARNING: Declaration of SmartList_Field::get_regular_database_fields($module) should be compatible with Fanatical\Core\v1a\Field::get_regular_database_fields($module, $include_fields = Array, $exclude_fields = Array) in file /mnt/sugar/shadowed/CLIENT.sugarondemand.com/modules/SmartList/includes/classes/SmartList/Field.php on line 33]