update-manager -d implies that pre-release version is a final release

This certainly affects Precise and may affect Saucy.

Hi!

I'm running Saucy Desktop and I am unable to upgrade it to Ubuntu 14.04 Beta using "update-manager -d"...

On Saucy, running as a regular user, "update-manager -d" doesn't show any option to upgrade to devel branch...

Is that expected, or am I facing this bug too?!

Thanks!
Thiago

Running update-manager -d now first displays a dialog saying "However, Ubuntu 17.10 is now available (you have 17.04)." After you click the "Upgrade..." button another dialog is displayed which talks about Artful Aardvark being in development and not to install it on production systems. Do you think that is sufficient?

No, it is not sufficient, it is still lying to the user. Ubuntu 17.10 is not available. If the next version of Ubuntu does turn out to be called 17.10 (which is highly likely, but not certain), it will become available in October.

The failure case is also confusing: it you can’t upgrade to the development version, because you aren’t running the latest release, you either get “The software on this computer is up to date”, which is a non-sequitur; or you get a list of updates for the current release, which is also irrelevant to what you asked for.

I guess that both these problems have the same cause: update-manager is behaving exactly as it normally would, with the exception of pretending that development versions are stable releases, instead of giving a coherent response to what you wanted when you typed -d.

So to outline a possible solution, if someone enters update-manager -d:

0. Don’t check for, or show, updates for the current release at all.

1. If you’re already using the development version, say so: “This computer is already using the Ubuntu development version ({codename}).”

2. Otherwise, if it’s the brief period where there isn’t a development version open, display something like “There is no Ubuntu development version at the moment. Try again in a few days.”

3. Otherwise, if you aren’t running the current release, display something like: “To upgrade to the development version, you need to upgrade to {current release} first.” (For bonus points, add a button to start that process.)

4. If you *are* running the current release, skip directly to the dialog that talks about the development version being in development and not to install it on production systems.

If it was easier to implement initially, steps 1, 2, and 3 could be output to the console.