tl;dr
my system thinks it's supposed to download packages for bionic even though I am still on xenial. I can't upgrade from xenial to bionic, because I should first upgrade all available packages. When I try to do that, it downloads bionic packages and then aborts, since the OS version doesn't match the new package versions. How do I tell my system it is still xenial and not bionic, yet?
I began running the ubuntu upgrade program as explained on this website. So:
sudo apt update
sudo apt upgrade
sudo apt dist-upgrade
sudo apt autoremove
sudo apt autoclean
then commenced running the upgrade program (after confirming I had installed update-manager-core) with
sudo do-release-upgrade
and everything went as expected. Good so far. It asked me whether I wanted to proceed with "y" or "N" or see details with "d". For fun, I hit "d" and "enter". I look at details in the terminal. OK, that's all very interesting. Anyways. Upon reaching the end, it shows me
(END)
here's where I should have stopped and opened this here website instead of doing something stupid. I hit "enter", nothing happened, "escape" nothing happened, "backspace" nothing happened. Then I chose to hit "Ctrl+C" and the upgrade program aborted and I got taken back to the previous terminal content, but without prompt. I tried "y" to continue with the distro upgrade, but that failed. Alright, close the terminal, reopen it, do sudo do-release-upgrade again. Something went wrong, but I don't remember what at this point. In any case, I rebooted the whole system, opened the terminal and now we're here:
thymaro@ultra:~$ sudo do-release-upgrade
Checking for a new Ubuntu release
Please install all available updates for your release before upgrading.
thymaro@ultra:~$ sudo apt-get update
Hit:1 http://it-mirrors.evowise.com/ubuntu bionic InRelease
Hit:2 http://it-mirrors.evowise.com/ubuntu bionic-updates InRelease
Hit:3 http://archive.canonical.com/ubuntu bionic InRelease
Hit:4 http://it-mirrors.evowise.com/ubuntu bionic-backports InRelease
Hit:5 http://it-mirrors.evowise.com/ubuntu bionic-security InRelease
Reading package lists... Done
thymaro@ultra:~$ sudo apt-get -y dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
account-plugin-facebook account-plugin-flickr account-plugin-google
.... {list of hundreds more packages}
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
checkbox-converged checkbox-gui curl gir1.2-totem-plparser-1.0
.... {list of dozens more packages}
The following NEW packages will be installed:
apache2-bin autopoint binutils-common binutils-x86-64-linux-gnu bolt
.... {list of hundreds more packages}
The following packages will be upgraded:
a11y-profile-manager-indicator accountsservice acl acpid
.... {list of hundreds more packages}
2355 to upgrade, 615 to newly install, 77 to remove and 0 not to upgrade.
Need to get 1'505 MB/2'207 MB of archives.
After this operation, 2'269 MB of additional disk space will be used.
Get:1 http://it-mirrors.evowise.com/ubuntu bionic-updates/main amd64 libglvnd0 amd64 1.0.0-2ubuntu2.3 [47.0 kB]
Get:2 http://it-mirrors.evowise.com/ubuntu bionic-updates/main amd64 libwayland-egl1-mesa amd64 19.2.8-0ubuntu0~18.04.3 [6'892 B]
Get:3 http://it-mirrors.evowise.com/ubuntu bionic-updates/main amd64 libwayland-egl1 amd64 1.16.0-1ubuntu1.1~18.04.3 [5'464 B]
Get:4 http://it-mirrors.evowise.com/ubuntu bionic-updates/main amd64 libqt5dbus5 amd64 5.9.5+dfsg-0ubuntu2.5 [195 kB]
... {about a thousand more lines downloading 'bionic' packages}
The question is at the beginning of the post under tl;dr.
lsb_release -aThis could help you: https://askubuntu.com/questions/124017/how-do-i-restore-the-default-repositories – dariofac May 13 '20 at 13:59(END), pressQto exit the file viewer. – Jos May 13 '20 at 14:06