Both media-video/kmplayer-0.10.0a and 0.10.0c fail to compile, because I have cairo-1.6.4 without X support (on purpose). Build log attached below. (By the way, kmplayer-0.9.4a-r1 and 0.10.0 compile fine.)
Created attachment 155757 [details] kmplayer-0.10.0c.log
Created attachment 155759 [details] emerge-info
Created attachment 155761 [details] emerge-info Oops, the first emerge --info is somewhat messy.
Fixed in media-video/kmplayer-0.10.0c-r1. Thanks for your bug report.