Is the "Final Release" a "Development Release"?

The development release is the pre-release version of Ubuntu. It's the next future release.

• Using the development release means you want to be a tester. You want to discover problems and translate strings and file bugs. If that doesn't sound fun, then DON'T run the development release.

• Using do-release-upgrade with the -d flag will migrate you to the current development release.

• The development release is NOT supported here at AskUbuntu.

The final release is the released version of Ubuntu. We usually refer to a final release by it's release date (18.04, 19.10, 20.04, etc) or by it's release name (Bionic Beaver, Eoan Ermine, Focal Fossa, etc.)

• This is the recommended version for general use.

• This is the version at http://ubuntu.com/downloads

• This is the version supported here at AskUbuntu

• Using do-release-upgrade without the -d flag will migrate you to the next final release.

Note that the week around a release date does not need to be confusing:

• On release day, the development release converts into the final release.

• The next development release won't open for a week or so. During this brief time, the -d flag may have unexpected results. Maybe it will bring you to the final release, or maybe it will bring you to the next development release. Read your output carefully.

For folks thinking about upgrading to a new release of Ubuntu:

• LTS Users (only): The tested upgrade path is NOT from, for example, 18.04 to 20.04. It's from 18.04.x to 20.04.1. That .1 release will occur three months after the main release. In other words, keep running the older LTS release for three more months, then your system will offer to upgrade.

• Impatient LTS users: Some folks don't want to wait. They want a newer release right away. These folks probably should be using Interim (6-month) releases instead of LTS, but that's not important here. There are shiny unofficial websites that suggest using update-manager -d or do-release-upgrade -d to skip that three month wait, and migrate from LTS to LTS right now. The safe route is to wait for the point release. Be patient. If you decide to use -d, read your output carefully to be sure you are getting the release that you expect.

• Interim (6-month) Release users: You do need to use -d to upgrade for the next few months. Since this is an LTS, the regular (non -d) upgrade won't be offered until 20.04.1. Reason: There's one mechanism, and it cannot tell the difference between interim releases and LTS releases. This is normal behavior for an LTS release, and occurs once every two years.

The offical upgrade path from LTS to LTS will be opened after 20.04.1 is released.

To override this, option -d that means "development" is used.

It is a "forced" upgrade, that's why you get the "development release" message.