It's my understanding that upgrades from Ubuntu 16 to Ubuntu 18 should be enabled after the 18.04.1 release. According to the release schedule, this release came out on July 26.
I am running Ubuntu 16.04.5. I've run
sudo apt update
sudo apt upgrade
sudo apt dist-upgrade
Then, I try to run
sudo do-release-upgrade
However, this fails. The output is:
Checking for a new Ubuntu release
No new release found.
Can anyone explain next steps? I've been browsing recent questions, and it seems that others have managed the upgrade. I'll be happy to post other relevant system info if needed.
This is not a duplicate of the suggested thread, because the upgrade is actually available now. Anyway, I have written my own answer to the question already.