Comment 2 for bug 160293

Additional information: it appears that this only happens when it is not connected directly to the internet, or (in my case) is missing proxy settings from apt.conf, or has them incorrect (we use a proxy here). On a later install with apt proxy settings correct, it showed the packages I needed and downloaded them fine. So, the issue probably only appears for someone who does not have direct internet access, but this is when it would be needed.