Gentoo Linux overlay containing additional ebuild files.
The repo comes with a ready repos.conf file you just need to add
to your /etc/portage/repos.conf/ dir:
curl -sL https://raw.githubusercontent.com/hacking-gentoo/overlay/master/repos.conf > /etc/portage/repos.conf/hacking-gentoo.conf
emerge --sync
layman -o https://raw.githubusercontent.com/hacking-gentoo/overlay/master/overlay.xml -f -a hacking-gentoo