Re: Cross-platform detection of multiarch

[Jonathan Nieder <jrnieder@gmail.com>]

Hi Jan,

Jan Medlock wrote:

> What is the recommended way to detect the presence of multiarch in a
> cross-platform build?
[...]
> Currently, there's an explicit check for Ubuntu 11.04

Thanks for raising this.  Of course, multiarch in Debian is young so
there is still a chance to make changes to improve this kind of use
case before a release.  As you hinted, other platforms may have other
ways to solve the same problems.

I would be very interested to hear about how the presence of multiarch
affects sage's build, and maybe we can come up with a generic solution
(like adding a new variable to getconf, things like that).  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).

For example: the best practice for installing a library for a long
time has been to write to $prefix/lib by default and allow this to be
overridden (for example to /usr/lib64 or /usr/lib/$(dpkg-architecture
-qDEB_HOST_MULTIARCH)) at build time.  I don't think multiarch changes
that.

To give another example: if you want to see where gcc looks for
libraries for some reason, there is "gcc -print-search-dirs".

Looking forward to your thoughts,
Jonathan