I've verified this fix on Ubuntu 16.04 LTS.
(xenial-amd64)root@impulse:/home/bdmurray# apt-cache policy ubuntu-release-upgrader-core ubuntu-release-upgrader-core: Installed: 1:16.04.30 Candidate: 1:16.04.30 Version table: *** 1:16.04.30 500 500 http://ubuntu.osuosl.org/ubuntu xenial-proposed/main amd64 Packages 100 /var/lib/dpkg/status 1:16.04.29 500 500 http://ubuntu.osuosl.org/ubuntu xenial-updates/main amd64 Packages 1:16.04.25 500 500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages 1:16.04.12 500 500 http://ubuntu.osuosl.org/ubuntu xenial/main amd64 Packages
(xenial-amd64)root@impulse:/home/bdmurray# do-release-upgrade Checking for a new Ubuntu release Get:1 Upgrade tool signature [819 B] Get:2 Upgrade tool [1242 kB] Fetched 1243 kB in 0s (0 B/s) authenticate 'bionic.tar.gz' against 'bionic.tar.gz.gpg' extracting 'bionic.tar.gz'
I've verified this fix on Ubuntu 16.04 LTS.
(xenial- amd64)root@ impulse: /home/bdmurray# apt-cache policy ubuntu- release- upgrader- core release- upgrader- core: ubuntu. osuosl. org/ubuntu xenial- proposed/ main amd64 Packages dpkg/status ubuntu. osuosl. org/ubuntu xenial-updates/main amd64 Packages security. ubuntu. com/ubuntu xenial- security/ main amd64 Packages ubuntu. osuosl. org/ubuntu xenial/main amd64 Packages
ubuntu-
Installed: 1:16.04.30
Candidate: 1:16.04.30
Version table:
*** 1:16.04.30 500
500 http://
100 /var/lib/
1:16.04.29 500
500 http://
1:16.04.25 500
500 http://
1:16.04.12 500
500 http://
(xenial- amd64)root@ impulse: /home/bdmurray# do-release-upgrade
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [819 B]
Get:2 Upgrade tool [1242 kB]
Fetched 1243 kB in 0s (0 B/s)
authenticate 'bionic.tar.gz' against 'bionic.tar.gz.gpg'
extracting 'bionic.tar.gz'