Merging media-libs/libsdl-1.2.10 with dev-lang/nasm-0.98.38-r1 failed with errors `symbol `hidden' not defined before use'. After upgrading to dev-lang/nasm-0.98.39-r3 emerging succeded.
Uh, nasm-0.98.38-r1 has been removed one year ago... Update your system properly, using emerge --update --deep world.
Sure, but I just thought that updating DEPEND to reflect that incompatibility wouldn't hurt.