Public bug reported:
pmartine@starship:~$ sudo apt install update-manager-core
Reading package lists... Done
Building dependency tree
Reading state information... Done
update-manager-core is already the newest version (1:16.04.13).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
pmartine@starship:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [819 B]
Get:2 Upgrade tool [1 258 kB]
Fetched 1 258 kB in 0s (0 B/s)
authenticate 'bionic.tar.gz' against 'bionic.tar.gz.gpg'
extracting 'bionic.tar.gz'
Reading cache
Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Hit http://fr.archive.ubuntu.com/ubuntu xenial InRelease
Hit http://fr.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit http://download.virtualbox.org/virtualbox/debian xenial InRelease
Hit http://fr.archive.ubuntu.com/ubuntu xenial-backports InRelease
Hit http://security.ubuntu.com/ubuntu xenial-security InRelease
Hit http://packages.ros.org/ros/ubuntu xenial InRelease
Fetched 0 B in 0s (0 B/s)
AppStream cache update completed, but some metadata was ignored due to errors.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Updating repository information
Third party sources disabled
Some third party entries in your sources.list were disabled. You can
re-enable them after the upgrade with the 'software-properties' tool
or your package manager.
To continue please press [ENTER]
Get:1 http://security.ubuntu.com/ubuntu bionic-security InRelease [83,2 kB]
Get:2 http://fr.archive.ubuntu.com/ubuntu bionic InRelease [242 kB]
Get:3 http://fr.archive.ubuntu.com/ubuntu bionic-updates InRelease [88,7 kB]
Get:4 http://fr.archive.ubuntu.com/ubuntu bionic-backports InRelease [74,6 kB]
Get:5 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
[158 kB]
Get:6 http://security.ubuntu.com/ubuntu bionic-security/main i386 Packages [127
kB]
Get:7 http://security.ubuntu.com/ubuntu bionic-security/main Translation-en
[60,5 kB]
Get:8 http://security.ubuntu.com/ubuntu bionic-security/main amd64 DEP-11
Metadata [204 B]
Get:9 http://security.ubuntu.com/ubuntu bionic-security/main DEP-11 64x64 Icons
[29 B]
Get:10 http://security.ubuntu.com/ubuntu bionic-security/universe amd64
Packages [56,9 kB]
Get:11 http://security.ubuntu.com/ubuntu bionic-security/universe i386 Packages
[56,7 kB]
Get:12 http://security.ubuntu.com/ubuntu bionic-security/universe
Translation-en [33,4 kB]
Get:13 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 DEP-11
Metadata [6 820 B]
Get:14 http://security.ubuntu.com/ubuntu bionic-security/universe DEP-11 64x64
Icons [11,3 kB]
Get:15 http://security.ubuntu.com/ubuntu bionic-security/multiverse amd64
Packages [1 444 B]
Get:16 http://security.ubuntu.com/ubuntu bionic-security/multiverse i386
Packages [1 608 B]
Get:17 http://security.ubuntu.com/ubuntu bionic-security/multiverse
Translation-en [996 B]
Get:18 http://fr.archive.ubuntu.com/ubuntu bionic/main amd64 Packages [1 019 kB]
Get:19 http://fr.archive.ubuntu.com/ubuntu bionic/main i386 Packages [1 007 kB]
Get:20 http://fr.archive.ubuntu.com/ubuntu bionic/main Translation-en [516 kB]
Get:21 http://fr.archive.ubuntu.com/ubuntu bionic/main amd64 DEP-11 Metadata
[477 kB]
Get:22 http://fr.archive.ubuntu.com/ubuntu bionic/main DEP-11 64x64 Icons [245
kB]
Get:23 http://fr.archive.ubuntu.com/ubuntu bionic/restricted amd64 Packages [9
184 B]
Get:24 http://fr.archive.ubuntu.com/ubuntu bionic/restricted i386 Packages [9
156 B]
Get:25 http://fr.archive.ubuntu.com/ubuntu bionic/restricted Translation-en [3
584 B]
Get:26 http://fr.archive.ubuntu.com/ubuntu bionic/universe amd64 Packages [8
570 kB]
Get:27 http://fr.archive.ubuntu.com/ubuntu bionic/universe i386 Packages [8 531
kB]
Get:28 http://fr.archive.ubuntu.com/ubuntu bionic/universe Translation-en [4
941 kB]
Get:29 http://fr.archive.ubuntu.com/ubuntu bionic/universe amd64 DEP-11
Metadata [3 287 kB]
Get:30 http://fr.archive.ubuntu.com/ubuntu bionic/universe DEP-11 64x64 Icons
[8 420 kB]
Get:31 http://fr.archive.ubuntu.com/ubuntu bionic/multiverse amd64 Packages
[151 kB]
Get:32 http://fr.archive.ubuntu.com/ubuntu bionic/multiverse i386 Packages [144
kB]
Get:33 http://fr.archive.ubuntu.com/ubuntu bionic/multiverse Translation-en
[108 kB]
Get:34 http://fr.archive.ubuntu.com/ubuntu bionic/multiverse amd64 DEP-11
Metadata [49,7 kB]
Get:35 http://fr.archive.ubuntu.com/ubuntu bionic/multiverse DEP-11 64x64 Icons
[225 kB]
Get:36 http://fr.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
[303
