After latest upgrade of geoclue to version 2.5.7, i get this error when running redshift from command line. Similar message is shown in alert window when starting redshift from gui.
Trying location provider `geoclue2'... Using provider `geoclue2'. Using method `randr'. Waiting for initial location to become available... Unable to start GeoClue client: GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: 'redshift' disallowed, no agent for UID 1000. Access to the current location was denied by GeoClue! Make sure that location services are enabled and that Redshift is permitted to use location services. See https://github.com/jonls/redshift#faq for more information. Unable to get location from provider.
Just to make sure that this is indeed triggered by geoclue upgrade, i git cloned geoclue package locally and tried to rebuild it with older version 2.5.6. I also tried to install older geoclue package from Solus package repo but couldn't install it because of some other packages in repo depend on latest release '20', so this was easier approach.
After rebuild of geoclue with older sources and directly installing .eopkg package, my redshift starts normally now, without any error messages.