concerning llibva backport

[Felipe Sateler]

On 5 August 2016 at 18:15, James Cowgill <jcowgill at debian.org> wrote:
> On 05/08/16 22:47, Felipe Sateler wrote:
>> On 5 August 2016 at 17:24, James Cowgill <jcowgill at debian.org> wrote:
>>> On 05/08/16 21:03, Nicholas D Steeves wrote:
>>>> Hi Sebastian,
>>>>
>>>> I did a fresh build of libva-1.7.1-1~bpo+1 today, and noticed that it
>>>> was building against mesa-10.3.2-1+deb8u1 from Jessie.  I've been
>>>> testing it on a Jessie+backported mesa-11.1.3-1~bpo8+1, and the
>>>> packages I've been testing have also been built against mesa-10.3.x.
>>>> Do you think it's ok to build against mesa 10.3.2, or should we bump
>>>> the build deps of libva to pull in mesa from jessie-backports.  I'm in
>>>> favour of bumping the deps asap.  Additionally, I think it would also
>>>> be wise to bump the intel-vaapi-driver build-depend on libdrm-dev to
>>>> prevent it from being built against libdrm-2.4.58-2.
>>>
>>> Why? You realize that building against a newer version of mesa/libdrm
>>> won't affect the dependencies on the final package?
>>
>> In backports, it does. Dependencies are statisfied from stable if
>> possible, thus the build-depends needs to be tightened to force use of
>> the backported library.
>
> What I mean is that build-depending on a more recent package version
> doesn't necessarily[1] mean that version will be required at runtime and
> reflected in the Depends: lines. For example, mesa doesn't insert any
> dependencies into the users of libgl1-mesa-glx, so bumping the
> build-dependency will have no affect on the version of the package
> actually used at runtime. So if the downstream package doesn't use any
> new features in the more recent library, why bump the build-dependency?

Ah. I was unaware of that weirdness. Indeed the mesa symbols file set
all versions to 0, and does not provide a -dev package mapping. So the
dep would be useless.


-- 

Saludos,
Felipe Sateler