media-sound/alsa-driver dep is not needed by alsa-lib and should be removed.
Alsa-driver installs some header files (under /usr/include/sound/), without which alsa-lib is not going to compile.
I haven't any, and it build correctly
Hmm... strange. Perhaps the things have changed, I'll look into this.
Looks like you are right. I've removed the dependency from the ebuild. p.s. Why would you want alsa libraries without the drivers?
to compile programs that *requires* alsa-libs w/o installing alsa driver