Otherwise you can do ln -s /etc/passwd $out/foo echo "file misc $out/foo" >> $out/nix-support/hydra-build-products and get Hydra to serve its /etc/passwd file.
Otherwise you can do ln -s /etc/passwd $out/foo echo "file misc $out/foo" >> $out/nix-support/hydra-build-products and get Hydra to serve its /etc/passwd file.