Problem with running redshift

The problem is not with geoclue package. You don't need to install geoclue. It is because you have not configured Redshift. Redshift sets the color temperature according to your location. The simplest fix to this issue is to enable location services:
System Settings > Security & Privacy > Location services > Turn ON

But you can manually configure Redshift to set custom values for color temperature and location. For that, open up your browser and search for the latitude and longitude for your area, for example, new york latitude and longitude.

Once you get the values for latitude and longitude for your area, then search for Startup Applications in your computer. Most probably you will have the entry for Redshift. Click on the Redshift entry and then click Edit. Then in the command section enter this command:

redshift-gtk -l [LATITUDE]:[LONGITUDE] -t 6500:3400

Replace [LATITUDE] and [LONGITUDE] with your values. For example my command goes like:

redshift-gtk -l 20.5937:78.9629 -t 6500:3400

Note:- If for some reason you don't see the entry for Redshift in the startup applications menu, just click on the Add button instead of the Edit button, provide a name for example, Redshift and then enter the above command.

The values 6500 and 3400 represent the color temperature values for day and night respectively. The value 6500 makes no color changes and the screen is perfectly calibrated. If you want to eliminate blue light on day time also, change the value 6500 to 5500. Again you can have your own custom values. Just Save the settings and Reboot to apply changes.

Depending on your window manager you may have to manually allow Redshift to access GeoClue.

Edit GeoClue's config

sudo nano /etc/geoclue/geoclue.conf

Append the following lines to /etc/geoclue/geoclue.conf

[redshift]
allowed=true
system=false
users=

Then restart Redshift kill $(pgrep '[r]edshift*') && redshift-gtk & disown

Redshift stopped working in Ubuntu 16.04 (yes, still using it in 2020).

I edited my ~/.config/redshift.conf into the following:

[redshift]
temp-night=4500

location-provider=manual

[manual]
lat=55.953
lon=-3.189

Note: I'm using manual location provider (not geoclue2).