Re: Cross-platform detection of multiarch

[Jan Medlock <medlock-debian@turboshower.net>]

Jonathan Nieder wrote:
> Jonathan Nieder wrote:
>> After
>> reading the bug log you linked to, it's still unclear to me where
>> multiarch fits in (as not ld's change in defaults to
>> --no-copy-dt-needed, say).
> 
> Ah, stupid me: here's a link so others can start where I left off.
> 
>  http://groups.google.com/group/sage-devel/msg/e60dc9297efebeaa
> 
> Perhaps Python should be making use of "gcc -print-search-dirs"
> output.

I just dug through this and understand better now.

Debian uses a different solution for building Python 2.6 than that
used by Sage (and it looks like Ubuntu). There's a patch in Debian's
packages of Python 2.6 that essential adds
{/lib,/usr/lib}/$(DEB_HOST_MULTIARCH) to the library search path.
This solution is included in upstream Python 2.7.

Python's distutils (or whatever is setting the default library paths)
seems to be not using the compiler's ideas about the library path
(i.e.  gcc -print-search-dirs).  That seems broken to me...  Parsing
the library directory paths across multiple compilers must be hard.

Thanks for sending me down the right path.  It looks like I should
just patch my local versions until Sage upgrades to Python 2.7.  (And
even then, it'll require dpkg-dev to compile.)  And multiarch was not
really involved...

JM