Files OS Snap provides

[Mark Shuttleworth]

On 05/11/15 12:17, John Lenton wrote:
> On 5 November 2015 at 10:57, Mark Shuttleworth <mark at ubuntu.com> wrote:
>> On 05/11/15 11:52, Mark Shuttleworth wrote:
>>> devel is where stuff can change, stable is where it doesn't.
>> The other point you may not be aware of is that no snap will ever show
>> up for a series without the developer expressly saying so. In that
>> sense, we can be totally explicit about expectations; if you publish for
>> 16.04, you will know exactly what you are publishing onto, and exactly
>> what is there, and that we have promised to maintain it well.
>>
>> This is quite different to the current world, where stuff goes in the
>> archive and can be grandfathered into future releases just because
>> nobody bothered to look at it again.
> I like this very much. However, I was under the impression you had
> said that packages needed to continue to work across release upgrades,
> and this seems to fly in the face of that. Am I misunderstanding, was
> that misreported, or has the thinking evolved?

That was misreported.

You will be able to upgrade a device from the "Ubuntu 16.04 LTS" stable
series to the "Ubuntu 18.04 LTS" stable series if:

 * the manufacturer of that device says it should work
 * the necessary kernel snap is available in that series
 * any required snaps for that device are available in that series

Say you have installed some extra snaps ("packages" you called them)
from 16.04; when you ask to upgrade, you'll be told that you're going to
lose those snaps if you upgrade. At that point it is your choice if you
upgrade or not.

So, you can upgrade from 16.04 to 18.04 if that is sane for the device,
and when you do you will upgrade all the snaps if they exist in 18.04
and lose the ones that DON'T exist in 18.04. For that reason, snaps
don't need to magically work with a future platform that didn't exist
when they were created, and we don't have to worry about changes between
16.04 and 18.04 because snap publishers will get to see all of them
before they have to deal with all of them.

Mark