These ebuilds come from https://github.com/regen2/regen2-overlay.
If you have some problems, go to the official site first.
ntrack : A lightweight library for getting events on network online status changes ( https://launchpad.net/ntrack )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a regen2-overlay
For Paludis use this rsync : rsync://gentoo.zugaina.org/regen2-overlay-portage
If you have a problem : ycarus(-at-)zugaina.org