beta16 is not available in xenial yet:
juju-2.0: Installed: 2.0~beta15-0ubuntu2.16.04.1 Candidate: 2.0~beta15-0ubuntu2.16.04.1 Version table: *** 2.0~beta15-0ubuntu2.16.04.1 500 500 http://gb.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 100 /var/lib/dpkg/status 2.0~beta4-0ubuntu2 500 500 http://gb.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
beta16 is not available in xenial yet:
juju-2.0: 0ubuntu2. 16.04.1 0ubuntu2. 16.04.1 0ubuntu2. 16.04.1 500 gb.archive. ubuntu. com/ubuntu xenial-updates/main amd64 Packages dpkg/status 0~beta4- 0ubuntu2 500 gb.archive. ubuntu. com/ubuntu xenial/main amd64 Packages
Installed: 2.0~beta15-
Candidate: 2.0~beta15-
Version table:
*** 2.0~beta15-
500 http://
100 /var/lib/
2.
500 http://