[Ubuntu] Fwd: [GRASS-dev] ubuntu gis policy

[Sebastiaan Couwenberg]

On 09/16/2016 07:14 PM, Angelos Tzotsos wrote:
> On 09/16/2016 05:29 PM, Sebastiaan Couwenberg wrote:
>> On 09/16/2016 03:45 PM, Micha Silver wrote:
>>> Randal Hale
>>>> I'm one of the guys who was commenting on the confusion. Someone
>>>> commented that the naming is in keeping with Ubuntu policy. Which
>>>> probably for the Sys Admin crowd is perfect. We've got a weird blend
>>>> of Users who want software BUT (and I didn't up until this last
>>>> thread) understand the reasoning behind the naming. It is confusing. I
>>>> don't know if something on the PPA explaining it is warranted OR a
>>>> name change OR something on the package websites.
>>>>
>>> I'd suggest this: (clearest to me, and does not break the known Debian
>>> chain)
>>>
>>> "Experimental" (=Debian testing) --> "Current" (=Debian unstable) -->
>>> "Legacy" (=Debian stable)
>> The above is wrong. Packages in Debian migrate from unstable to testing
>> after a period of 5 to 10 days (depending on urgency of the package, 5
>> days for medium, 10 days for low) assuming no release critical bugs are
>> affecting the version of the package in unstable and all of the required
>> versions of dependencies are in testing or will migrate to testing on
>> the same day as the package in question.
>>
>> Debian testing is therefore less prone to issues than unstable in which
>> active development is done. The experimental repository is used for
>> packages which should not migrate to testing or are otherwise unfit for
>> inclusion in the next Debian stable release via the testing repository.
>> This includes packages which require a transition (rebuilds of all its
>> reverse dependencies) to have a coherent package set migrate to testing.
>> Not all maintainers adhere to this, and uncoordinated transitions are
>> triggered by uploads to unstable which should have gone to experimental
>> first. We've recently had this for libdap & openmpi for example.
>>
>> The flow of packages in Debian is as follows:
>>
>>   (experimental ->) unstable -> testing -> stable
>>
>> New packages are uploaded to unstable by default, or experimental if
>> more work is required before they can migrate to testing (e.g. a
>> transition or wait for the final release in case of beta & RC
>> pre-releases), after the grace period the packages from unstable migrate
>> to testing, packages in testing get frozen eventually in preparation of
>> the next stable release. Because codenames are used for the
>> distributions the packages in testing aren't copied to stable, the
>> stable suite is simply renamed to oldstable and the testing suite to
>> stable. Hence the importance to use release codenames in apt
>> sources.list to stick to your chosen distribution and not be forced to
>> switch when the new stable release is out.
>>
>> Because of the abuse of the ubuntugis-testing repository for
>> experimental packages, that repository should be renamed to reflect its
>> use. Users and administrators of systems using the UbuntuGIS PPAs who
>> are uncomfortable by unpredictable changes should stick to the stable
>> PPA which is only infrequently updated. Reintroducing a testing PPA in
>> which more testing is performed by the users before those packages are
>> moved to the stable is valuable to root out bugs and integration issues,
>> but the UbuntuGIS userbase is not as involved as in Debian so the amount
>> of testing those packages would receive is likely to be very limited if
>> not non-existent. The packages in the UbuntuGIS PPAs are also not
>> subjected to automated QA as the packages in Debian are. Making the
>> value of an UbuntuGIS testing PPA questionable in practice.
>>
>> Most UbuntuGIS users use the unstable PPA because they want newer
>> upstream versions than the packages included in the Ubuntu LTS release,
>> and are not willing to wait until those version become available in the
>> UbuntuGIS stable PPA.
>>
>> Until more development manpower is available, especially someone willing
>> to lead the integration & testing work required for stable releases,
>> discussing the PPA naming is of little to no value. All eyes are focused
>> on the unstable PPA with hardly anyone caring for the other PPAs. If it
>> weren't for the updates from OSGeo-Live the UbuntuGIS PPAs would stop
>> being used due to irrelevance. Having lots of users doesn't mean having
>> enough developers to match. This is common in the Ubuntu world which has
>> lots of users but much less developers when compared to Debian. Ubuntu
>> users should learn to become developers for the ecosystem to flourish.
> 
> Thank you Bas for the detailed description.

And sorry for the typos which I've corrected in the above quote, some
important "not"s were missing but should be obvious in context.

> There have been many cases in the past, where system admins from well
> known organizations have said: "we accept packages from Debian/Ubuntu
> upstream OR UbuntuGIS". Some of them have explicitly asked for UbuntuGIS
> stable or else they would not accept to deploy packages from other
> sources. This IMO means that there is a developed trust of people to our
> stable ppa even if the packages there are not changing often. But as
> already said, our unstable ppa is still the most popular, due to the
> update rate.

Regarding hesitation to the unstable name. Those administrators are
advised to remember that Ubuntu syncs its packages from Debian unstable
for its new releases, not Debian stable. Especially for packages in
universe Ubuntu doesn't generally make any modifications and just takes
the packages from Debian as-is.

The release codename for Debian unstable is sid, named after the Toy
Story character due to his tendency to break toys, and has since become
a backcronym for still-in-development. The name should be considered to
reflect its active development where some breakage may occur.

Because packages in Debian unstable are intended to migrate to testing,
their quality is usually just as good as in a stable release, because if
there are no bugs, release critical or otherwise, the package eventually
ends up in the stable release without modifications. During the
development cycle packages in the Debian testing, unstable and
experimental repositories are subjected to various QA test (most of whom
are automated), these discover bugs which are then fixed in subsequent
revisions of the package, improving the quality before their inclusion
in the next stable release.

Most Debian users run the stable distribution on their systems. Users
wanting more recent packages but not be subjected to the bleeding edge
immediately after new packages are uploaded run testing, and developers
tend to have at least some systems running unstable. You notice this in
bugreport activity, the bugreports for the version in unstable tend to
be from the QA systems, and once the packages migrate to testing more
bugreports from users tend to be filed. If an important bug makes it
into the stable release, you get lots of bugreports after the new stable
release is out.

UbuntuGIS doesn't have this spread of users and systems doing testing of
the packages in the PPAs, which is a shame because early testing by
users before the new version reaches stable is very valuable. Having an
official policy for UbuntuGIS on which users can base their expectations
which PPA to use may bring some of the benefits that Debian gets from
its userbase.

> I believe that we should not touch the names of stable and unstable ppas.

Agreed, especially since the URLs cannot be changed. ubuntugis-stable is
only the display name for example, the URL is /ppa.

> Now regarding testing ppa, I think it was dead before we decided to sync
> it with OSGeoLive nightly, so renaming it to experimental makes sense to
> me. I agree that there is no man power available at the moment for an
> actual Testing ppa, I think the OSGeo-Live releases practically have
> this role today. This is why I have proposed to move well tested
> OSGeo-Live packages to stable after some time.

Also agreed. The current method to take the packages from OSGeo-Live is
the best we can do for UbuntuGIS with the currently available manpower.

Kind Regards,

Bas

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