apt policy tmate
tmate:
  Installed: (none)
  Candidate: 2.2.1+201706011546+stable3~ubuntu17.10.1
  Version table:
     2.2.1+201706011546+stable3~ubuntu17.10.1 500
        500 http://ppa.launchpad.net/tmate.io/archive/ubuntu artful/main amd64 Packages
     2.2.1-1build1 500
        500 http://de.archive.ubuntu.com/ubuntu artful/universe amd64 Packages