"emerge net-libs/serf" throws a fetch error: >>> Downloading 'http://artfiles.org/apache.org/serf/serf-1.3.8.tar.bz2' --2018-12-10 21:51:28-- http://artfiles.org/apache.org/serf/serf-1.3.8.tar.bz2 Resolving artfiles.org... 80.252.110.38, 2a00:1f78:af:11::2 Connecting to artfiles.org|80.252.110.38|:80... connected. HTTP request sent, awaiting response... 404 Not Found 2018-12-10 21:51:28 ERROR 404: Not Found. There are only files for version 1.3.9 on http://apache.mirrors.hoobly.com/serf/
Please set your GENTOO_MIRRORS variable in make.conf to a valid value (that's not blank) and you will be able to download 1.3.8-r*. The files are mirrored in Gentoo for this exact purpose when upstreams feel all old versions should be pulled.
Thank you for the solution! I had the GENTOO_MIRRORS point to http://mirror.switch.ch/ftp/mirror/gentoo/ which was decommissioned some time ago. I now switched to https://mirror.init7.net/gentoo/ and the install works. BTW: This new mirror is not listed in https://gentoo.org/downloads/mirrors/. Who is responsible for this list?