[Buildroot] [PATCH 1/1] package/libpng: allow selection of older libpng versions

[Paul Cercueil <paul@crapouillou.net>]

Le dim. 21 juil. 2019 ? 10:22, "Yann E. MORIN" 
<yann.morin.1998@free.fr> a ?crit :
> Thomas, Paul, Al,
> 
> On 2019-07-21 15:49 +0200, Thomas Petazzoni spake thusly:
>>  On Sun,  7 Jul 2019 12:52:24 -0400
>>  Paul Cercueil <paul@crapouillou.net> wrote:
>>  > By allowing building an older version of libpng, we can create 
>> Buildroot
>>  > systems that are still binary-compatible with applications 
>> compiled with
>>  > older Buildroot toolchains.
>>  While I understand what you're trying to do, I'm not sure it's a
>>  reasonable goal for Buildroot to be able to provide binary
>>  compatibility between systems generated by different Buildroot
>>  versions. We regularly update libraries to their latest upstream
>>  versions, and sometimes they break the ABI compatibility. I don't 
>> think
>>  we want to enter the game of ensuring that ABI compatibility is 
>> ensured
>>  between Buildroot versions.
> 
> Agreed.

Honestly, in our case the only thing needed to support apps compiled 
with Buildroot 2014.05 with the new Buildroot 2019.02.1 is this patch, 
and a few symlinks in /lib (since libm/librt/etc. are gone). 
Thanksfully the major version of libraries doesn't change that often.


>>  If you're building a program with a given Buildroot SDK, it should 
>> be
>>  executed on the Buildroot system that matches that SDK.
> 
> Agreed.

Then that means we're stuck with a 2014.05 Buildroot and cannot 
contribute to upstream Buildroot development. It's not ideal.


> Regards,
> Yann E. MORIN.
> 
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