HowTo install YaCy on Gentoo

Gentoo Bug for yacy: https://bugs.gentoo.org/show_bug.cgi?id=100108

Current available ebuilds from overlays: http://gpo.zugaina.org/Search?search=yacy

For example

layman -a flow && emerge net-misc/yacy

Converted from https://wiki.yacy.net/index.php?title=En:GentooInstall, may be outdated