This question from 2013 Can I do a Silent or Unattended Release Upgrade?
explains how to upgrades to the new stable release without prompts:
$ do-release-upgrade -f DistUpgradeViewNonInteractive
However this does not work on my system:
$ do-release-upgrade
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [198 B]
Get:2 Upgrade tool [1'261 kB]
Fetched 1'261 kB in 0s (0 B/s)
authenticate 'yakkety.tar.gz' against 'yakkety.tar.gz.gpg'
extracting 'yakkety.tar.gz'
Reading cache
Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Get:1 http://ch.archive.ubuntu.com/ubuntu yakkety InRelease [247 kB]
...
However, $ do-release-upgrade -f DistUpgradeViewNonInteractive
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [198 B]
Get:2 Upgrade tool [1'261 kB]
Fetched 1'261 kB in 0s (0 B/s)
authenticate 'yakkety.tar.gz' against 'yakkety.tar.gz.gpg'
extracting 'yakkety.tar.gz'
and gets stuck here. It does not continue with the "Reading cache".
How to make an unattended release Upgrade from Ubuntu Ubuntu 16.04.1 LTS?
do-release-upgrade
without the-f DistUpgradeViewNonInteractive
option worked fast and fine. – David Portabella Oct 17 '16 at 14:07