x11-base/xorg-server-1.14.0 needs pixman >= 0.27.2, but >=x11-libs/pixman-0.21.8 is specified in xorg-server-1.14.0.ebuild. This means that package won't emerge succesfully on system which has pixman with version that is >=0.21.8 and <0.27.2.
Fixed in 1.14.1