Comment 9 for bug 1822886

I followed the test when upgrading a system from xenial to bionic and it passed. Here we can see that url_downloadable is called only once with the version of the release upgrader in -proposed and that the universe entry is still enabled:

2019-04-15 09:53:30,259 INFO Using config files '['./DistUpgrade.cfg.xenial']'
2019-04-15 09:53:30,260 INFO uname information: 'Linux clean-xenial-amd64 4.15.0-47-generic #50~16.04.1-Ubuntu SMP Fri Mar 15 16:06:21 UTC 2019 x86_64'
2019-04-15 09:53:30,527 INFO apt version: '1.2.31'
2019-04-15 09:53:30,527 INFO python version: '3.5.2 (default, Nov 12 2018, 13:43:14)
[GCC 5.4.0 20160609]'
2019-04-15 09:53:30,530 INFO release-upgrader version '18.04.31' started
...
2019-04-15 09:53:41,478 DEBUG examining: 'deb http://ubuntu.osuosl.org/ubuntu xenial main restricted multiverse'
2019-04-15 09:53:41,478 DEBUG verifySourcesListEntry: deb http://ubuntu.osuosl.org/ubuntu bionic main restricted multiverse
2019-04-15 09:53:41,478 DEBUG url_downloadable: http://ubuntu.osuosl.org/ubuntu/dists/bionic/Release
2019-04-15 09:53:41,478 DEBUG s='http' n='ubuntu.osuosl.org' p='/ubuntu/dists/bionic/Release' q='' f=''
2019-04-15 09:53:41,556 DEBUG entry 'deb http://ubuntu.osuosl.org/ubuntu bionic main restricted multiverse' updated to new dist
2019-04-15 09:53:41,556 DEBUG examining: 'deb http://ubuntu.osuosl.org/ubuntu xenial-updates main restricted multiverse'
2019-04-15 09:53:41,557 DEBUG entry 'deb http://ubuntu.osuosl.org/ubuntu bionic-updates main restricted multiverse' updated to new dist
2019-04-15 09:53:41,557 DEBUG examining: 'deb http://ubuntu.osuosl.org/ubuntu xenial-security main restricted multiverse'
2019-04-15 09:53:41,558 DEBUG entry 'deb http://ubuntu.osuosl.org/ubuntu bionic-security main restricted multiverse' updated to new dist
2019-04-15 09:53:41,558 DEBUG examining: 'deb http://ubuntu.osuosl.org/ubuntu xenial universe'
2019-04-15 09:53:41,558 DEBUG entry 'deb http://ubuntu.osuosl.org/ubuntu bionic universe' updated to new dist