media-sound/mpd-svn with USE flag 'mpc' need >=media-libs/libmusepack-1.1 to compile. It fails on older versions. (can't find musepack/musepack.h) Depend need to be modified
Oops, forgot to close this bug, sorry. I have fixed this in the ebuild (without a revision bump) about two days ago, it should be on your mirror.