media-libs/libepoxy-1.2 with abi_x86_32 flag should require x11-proto/xproto abi_x86_32 flag.
Presumably just for the pkgconfig .pc file in /usr/lib32/pkgconfig/?
Created attachment 436218 [details] libepoxy-1.3.1 build.log
Created attachment 436220 [details] libepoxy-1.3.1 config.log
Needed to recompile libepoxy-1.3.1 with abi_x86_32, it failed. The folks on #gentoo stated the ebuild needs ${MULTILIB_USEDEP} and told me to attach those both log files.
Created attachment 436226 [details, diff] libepoxy ${MULTILIB_USEDEP} patch After trying and recompiling, I patched all 3 libepoxy ebuilds so they use ${MULTILIB_USEDEP}. Compiled just fine here with 1.3.1.
Created attachment 436228 [details, diff] libepoxy abi_x86_32 patch Previous had 2 typos
commit 831e64cedcd599fcf164ff92ac936c8e896c011c Author: Chí-Thanh Christopher Nguyễn <chithanh@gentoo.org> Date: Mon Jul 4 19:37:06 2016 +0200 media-libs/libepoxy: fix mulitlib dependencies Bug: https://bugs.gentoo.org/show_bug.cgi?id=541088