[Debian-med-packaging] Bug#606004: What to do with “Fix FTBFS with ld --as-needed” bugs ?

[Matthias Klose]

On 06.12.2010 01:14, Charles Plessy wrote:
> Le Sun, Dec 05, 2010 at 02:57:53PM +0100, Matthias Klose a écrit :
>> Package: samtools
>> Version: 0.1.12a-1
>> Tags: patch
>> User: debian-gcc at lists.debian.org
>> Usertags: ld-as-needed
>>
>> patch at
>> http://launchpadlibrarian.net/60144486/samtools_0.1.12a-1_0.1.12a-1ubuntu1.diff.gz
>
> Dear Matthias,
>
> thank you for your patch.
>
> I do not know that to do with it since I have difficulties to understand the
> context. It is a patch for Ubuntu but it is usertagged with the Debian GCC's
> team email. I have a couple of questions, and since some of them may be of
> general interst, I am copying debian-devel.
>
>   - Is there a timeline in which the package in Debian will stop to build from
>     source if the patch is not applied ?
>
>   - I do not understand what problem the patch solves when reordering ‘-lm -lz
>     -L.. -lbam’ to ’-L.. -lbam -lm -lz’. It seems that it is related to the use
>     of --as-needed. Is there a general explanation somewhere, that I can use
>     when forwarding the patch upstream ?
>
>   - Does such a change represents some best practice that we should put forward
>     for our uptreams to be aware of, for instance in http://wiki.debian.org/UpstreamGuide ?

the order of objects on the command line is significant for traditional linkers, 
and older binutils.  So while this kind of failures may not seen with current 
binutils, you may see this with other linkers or older binutils. Such changes 
are safe to make.

For further reference please see my email to debian-gcc and debian-ports, and
http://wiki.debian.org/ToolChain/DSOLinking

   Matthias