'emerge -v1 ati-drivers' fails with: ... >>> Emerging (2 of 333) x11-drivers/ati-drivers-15.11::x11 >>> Downloading 'http://distfiles.gentoo.org/distfiles/radeon-crimson-15.11-15.30.1025.zip' --2015-12-26 10:59:15-- http://distfiles.gentoo.org/distfiles/radeon-crimson-15.11-15.30.1025.zip Resolving distfiles.gentoo.org (distfiles.gentoo.org)... 64.50.233.100, 156.56.247.195, 216.165.129.135, ... Connecting to distfiles.gentoo.org (distfiles.gentoo.org)|64.50.233.100|:80... connected. HTTP request sent, awaiting response... 404 Not Found 2015-12-26 10:59:15 ERROR 404: Not Found. ... Trying to download manually radeon-crimson-*.zip I find only radeon-crimson-15.12-15.302-151217a-297685e.zip, which is not acepted by 'emerge -v1 ati-drivers'.
Dropped the ati-drivers ebuilds from the x11 overlay.