The non-mingw code path in src_compile() lacks an 'emake' call. As a result, the library is compiled in src_install().
should be all set now in the tree; thanks for the report! Commit message: Fix transposed emake http://sources.gentoo.org/sys-libs/zlib/zlib-1.2.8.ebuild?r1=1.1&r2=1.2
Thanks, will try to work on multilib ported ebuild when I am able to :)