My Gentoo overlay with ebuilds related to VDR & more...
To install it, just get the overlay description file overlay_gen2ovl-googoo2.xml and place it in your layman storage directory, then reference it in /etc/layman/layman.cfg under the "overlays:" section as follows:
file://%(storage)s/overlay_gen2ovl-googoo2.xml
Alternatively, on newer layman versions, you can just place it in the /etc/layman/overlays directory (but then do not reference it in the config file).
Then you can effectively add the overlay by issuing the command:
layman -f -a gen2ovl-googoo2
Have phun!