I use the geoclue pacakge for redshift to detect sunrise and sunset times and adjust my screen colouring accordingly.
Running /usr/lib/geoclue-2.0/demos/where-am-i I see:
** (where-am-i:22125): CRITICAL **: 15:16:11.080: Failed to connect to GeoClue2 service: GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: 'geoclue-where-am-i' disallowed, no agent for UID 1000
To use the where-am-i demo, you need to start an agent. The agent is not necessary for applications that you add to geoclue.conf . However you need to add the name of the desktop file without the desktop extension.