According to systemd.special(7), nss-lookup.target is a Special Passive System Unit. This means that services depending on its functionality should order themselves after the target with an After= type dependency, but should not have a Wants= dependency for them. Therefore, nss-lookup.target should be pulled in by the providing services instead, or the consumer services will never be able to order themselves after the providing services since nss-lookup.target would not be pulled in at any point in the boot process. dnscrypt-proxy.service provides name lookup functionality, and has a Before= dependency on nss-lookup.target. However, it should have a Wants= dependency on it as well in order to indicate readiness of name lookup functionality.