When creating your own binhost downstream of another binhost -- e.g. you use Gentoo's official binhost described at https://wiki.gentoo.org/wiki/Project:Binhost but also build your own packages for things not covered by the official one -- it is disruptive to end up with binary packages that are duplicates of your upstream binhost, copied into your own binhost. I'd like to be able to specify a PKGDIR that is used whenever I run emerge --buildpkg, and a different directory which is used by --getbinpkg. This would allow me to re-host only the former. Users would be expected to enable multiple binhosts and get packages from whoever originally created them; I wouldn't be responsible for monitoring the server footprint of files I didn't create. This would also mean that it's trivially possible to rm -rf the remote downloads bincache to recover space, without running the risk of deleting binaries that will suddenly no longer be available anywhere.
Fixing this would also make it easier for us to default-on signature verification (binpkg-request-signature) because we don't suddenly require sigs from locally built binpkgs.
