media-libs/nas-1.7-r1 wont compile due to lack of packages: gccmakedep, imake (no xmkmf) and rman. I had to add them manually, after that everything works ok. I'm using modular xorg.
<snip> RDEPEND="|| ( ( x11-libs/libXt x11-libs/libXau x11-libs/libXaw x11-libs/libX11 x11-libs/libXres x11-libs/libXTrap x11-libs/libXp ) virtual/x11 )" DEPEND="${RDEPEND} || ( ( x11-misc/gccmakedep x11-misc/imake app-text/rman x11-proto/xproto ) virtual/x11 )" </snip> Wipe any mention of virtual/x11 from every file in /etc/portage.
(In reply to comment #1) > Wipe any mention of virtual/x11 from every file in /etc/portage. This causes problems with "emerge -u world" See: http://gentoo-wiki.com/HOWTO_Modular_Xorg#.27emerge_-u_world.27_wants_to_install_xorg-x11_6.x_or_virtual.2Fx11