в man make.conf пишут то, что я ниже скопировал. Но мне неясно, что это означает и как использовать эту переменную.
PORTAGE_BINHOST_HEADER_URI = "ftp://login:pass@grp.mirror.site/pub/grp/i686/athlon-xp/"
This variable only makes sense on a system that will serve as a binhost and build packages for clients. It defines the URI header field for the package index file which is located at ${PKGDIR}/Packages. Clients that have PORTAGE_BINHOST properly configured will be able to fetch the index and use the URI header field as a base URI for fetching binary packages. If the URI header field is not defined then the client will use it's ${PORTAGE_BINHOST} setting as the base URI.
