Created attachment 281253 [details] sdl-mixer-1.2.11-r1-build.log The final linking stage gets flags from something like $(pkg-config --cflags --libs sdl), ignoring the user's desired LDFLAGS/CFLAGS. In a normal autotools configuration, linking a final shared object or executable passes the user's CFLAGS and LDFLAGS to libtool.
Created attachment 281255 [details] emerge --info
Created attachment 281261 [details, diff] sdl-mixer-1.2.11-multilib.patch Fixes the compilation issue for me on portage-multilib by adding CFLAGS and LDFLAGS to libtool's commandline when linking the final .so.
Comment on attachment 281261 [details, diff] sdl-mixer-1.2.11-multilib.patch really should get upstream to convert to automake. but until then, patch looks fine ...
in portage. thanks for the bug report and patch.