The feature flag SYNC_ALL_LOCATIONS
has been removed from the CommCareHQ codebase. This flag was marked as deprecated back in 2017 and is understood to not be in use. We're announcing this here just in case someone has turned it on on a self-hosted environment. If you need that functionality, it can be achieved in-product through the advanced Organization Level configuration screen. (Set "level to expand from" to "root")