Why does do-release-upgrade from 16.04 LTS to 16.10/17.04 not find updates even with --devel-release?

Question

I'm trying to upgrade a server (CLI only) from Ubuntu 16.04 to a newer non-LTS release using the do-release-upgrade tool.

I know LTS versions usually don't upgrade to 'non-LTS' releases prompting. Some assorted (old...) forum posts seem to imply that the -d, --devel-release option should be enough to force the update, but even that does not find anything.

I've tried various combinations of -c and -d.

There's also lots of people discussing how to upgrade from 14.04 to 16.04, where apparently it now waits for the next point release (16.04.1) first. But that's not relevant here, as I'm trying to upgrade away from LTS.

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The exact message is:

# do-release-upgrade -c -d
Checking for a new Ubuntu release
No new release found

My current version is 16.04.2:

# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.2 LTS
Release:        16.04
Codename:       xenial

Answer 1

So by default it'll only try and upgrade to the next LTS release, and it'll only do so at version '.10' for 'reasons'...?

So to change it manually on either a desktop version or server version you can edit the file where this is set using vi:

sudo vi /etc/update-manager/release-upgrades
# Find the line that reads:
Prompt=LTS
# Change it to say:
Prompt=normal

Save the file, then run the upgrade again

do-release-upgrade

And it should upgrade as expected, to the next version (non-lts).

Note: You can do the same thing in reverse, to set it to only upgrade to the next LTS version too.