Gentoo ebuild overlays managed through layman have been slightly overhauled recently. We’ve chosen to update our overlays before the old specification is deprecated. If you use any of our overlays, edit the file /etc/layman/layman.cfg and replace the URL as follows:
OLD:
http://github.com/svoop/bitcetera-overlay/raw/master/layman.xml
NEW:
http://github.com/svoop/bitcetera-overlay/raw/master/repositories.xml