I use a slackware64-current system with the latest AlienBob's multilib packages and everything works fine. I use the multilib mainly to run MS Office through Wine for my work.
I usually compile some stuff myself (x264, ffmpeg, libdrm, mesa, things like that, usually git pulls) without any problem.
However, I seem to have a problem compile mesa git recently, the last time I managed to compile it was the 22/12/2012.
Now it fails with the following messages :
gmake : on entre dans le répertoire « /usr/src/CVS/mesa/src/gallium/targets »
Making all in dri-r300
gmake : on entre dans le répertoire « /usr/src/CVS/mesa/src/gallium/targets/dri-r300 »
/usr/lib/libexpat.so: could not read symbols: File in wrong format
collect2: error: ld returned 1 exit status
gmake: *** [r300_dri.la] Erreur 1
gmake : on quitte le répertoire « /usr/src/CVS/mesa/src/gallium/targets/dri-r300 »
gmake: *** [all-recursive] Erreur 1
It obviously try to link with the 32bits lib instead of going for the 64bits one in /usr/lib64 but can't find out why. The build use proper ARCH and /usr/lib64 dir for libs, everything else compiles fine on this system and creates proper 64bits files. I suspect something wrong in the current mesa code but I'm not knowledgeable enough to know where to fix it.
I use basically the same build options for configure as the official mesa Slackbuild.
If anyone has a clue where to look for, I'm interested!