That's not possible at the moment Gilles, as ia32-libs simply (stupidly) takes the i386 package files rather than rebuilds them. So any build options for 32-bit ia32-libs would also have to be in the real 32-bit package as well (where /usr/lib32 is incorrect).
That's not possible at the moment Gilles, as ia32-libs simply (stupidly) takes the i386 package files rather than rebuilds them. So any build options for 32-bit ia32-libs would also have to be in the real 32-bit package as well (where /usr/lib32 is incorrect).