with media-libs/libmng-2.0.2[abi_x86_32] (available in ~amd64), libmng.so.1 has been replaced with libmng.so.2. In emul-linux-x86-qtlibs, the file "/usr/lib32/qt4/plugins/imageformats/libqmng.so" links so libmng.so.1. This is causing the preserved-rebuild system to hold libmng.so.1 installed: >>> package: app-emulation/emul-linux-x86-baselibs-20131008-r19 * - /usr/lib32/libmng.so.1.0.0 * used by /usr/lib32/qt4/plugins/imageformats/libqmng.so (app-emulation/emul-linux-x86-qtlibs-20131008) But on new installations, this would not be present, so the link would be broken. Please rebuild emul-linux-x86-qtlibs to reference the new version, and add a dependency on >=media-libs/libmng-2.0.2[abi_x86_32]
Apparently libmng.so.1 is included in emul-linux-x86-baselibs again (as of at least 20140406-r1), so this is fixed.