Bug#650601: transition: libpng 1.5

[Nobuhiro Iwamatsu <iwamatsu@debian.org>]

Hi, Michael.

Sorry, reply was late, and thanks for your comment.

2012/3/5 Michael Biebl <biebl@debian.org>:
> On 25.02.2012 21:22, Cyril Brulebois wrote:
>> Adam D. Barratt <adam@adam-barratt.org.uk> (05/12/2011):
>>> On Mon, 2011-12-05 at 16:34 +0900, Nobuhiro Iwamatsu wrote:
>>>> First, we had better upload libpng15, after changing libpng12-dev
>>>> into libpng-dev.  Surely, I think that this method is easy for
>>>> shift.
>>>
>>> We appear to have different definitions of "easy".  Anything that
>>> involves changes to and uploads of over 300 packages is not what the
>>> release team classifies as easy.
>>
>> I set up a tracker in the meanwhile:
>>   http://release.debian.org/transitions/html/libpng1.5.html
>>
>> and it doesn't qualify as “easy” by my standards either.
>
>
> Seems there has been a MBF regarding changing the build-depedency from
> libpng12-dev to libpng-dev.
> Reading through #650601 and seeing the amount of packages affected, I
> think the proposed plan is not good for several reasons.
> a/ virtual provides can't safisfy versioned dependencies
> b/ switching blindly from libpng12-dev to libpng-dev doesn't mean the
> package will actually build against libpng15
> c/ testing migration will be a night mare.
>
> What about the following:
> - Make libpng12 and libpng15 co-installable, by using different source
> package names, e.g. src:libpng and src:libpng15
> - src:libpng12 builds libpng12-dev, src:libpng15 builds libpng15-dev
> - upload *both* packages to unstable
> - src:libpng12 builds a real package libpng-dev, which depends on
> libpng12-dev (with a strict dep), this way versioned build-depends can
> be satisfied.
> - let both packages migrate to testing
> - tell maintainers to test their packages against libpng15, and do the
> following:
>   1/ if it builds against both libpng12 and libpng15, change the b-dep
> to libpng-dev
>   2/ if it needs updates for libpng15 and the change is not backwards
> compatible, b-depend on libpng15-dev
> - when all packages have been updated to depend on either libpng-dev or
> libpng15-dev, make src:libpng15 build libpng-dev and make it depend on
> libpng15-dev and binNMU the remaining lot.
>
> This way, we don't need to start a huge transition, which has the
> potential to block other transitions due to testing migration.
>
>
> How does that sound?

I understood all it.
I am working about this with Anibal. We will upload libpng1.5 this week.

Best regards,
  Nobuhiro

-- 
Nobuhiro Iwamatsu
   iwamatsu at {nigauri.org / debian.org}
   GPG ID: 40AD1FA6