Re: How does one specify linking to 64 bit libraries when there is a choice?

[Ralf Wildenhues]

* Bruce Korb wrote on Mon, Dec 20, 2010 at 03:09:48PM CET:
>   How much understanding of the machinery should be expected
>   of the hapless project builder?

I've skimmed most of the conversation in this thread now.

The crucial part, I think, is *not* the --libdir setting.  Distros
usually get that consistent between their packages, and users should not
be using any of /usr/lib{,32,64} but rather something below /usr/local.

One crucial part is that libtool gets confused whenever it has
directories with the wrong ABI in the search path (unlike ld or ld.so,
both are in some cases smart enough to skip wrong ABI), which means that
either no instance of the build system machineries may introduce such
paths, or libtool needs to get smarter to ignore wrong ABI dirs.

The other crucial part is that libtool doesn't get the
sys_lib_search_path_spec and sys_lib_dlsearch_path_spec settings
right on several distros, introducing such wrong directories itself (not
to speak of cross setups).  There have been several proposed patches to
address this, e.g.
http://thread.gmane.org/gmane.comp.gnu.libtool.patches/10625
http://thread.gmane.org/gmane.comp.gnu.libtool.patches/9931
but I have yet to see one that solves it.

Thanks,
Ralf