RepeatIt adds "repeat song", "repeat clip" and "intro seek" to xmms. It wasn't quite what I was looking for, but I realized that after creating this ebuild. Maybe someone else finds it useful.
Created attachment 37137 [details] media-plugins/xmms-repeatit
Created attachment 37197 [details] media-plugins/xmms-repeatit-0.0.4.ebuild Looks great (i'm unable to test now). Only a cosmetic change: die -> die "ERRORMESSAGE"
in portage; thanks :)