
When blocklists are built with a derivation, using extraHosts would require IFD, since the result of the derivation needs to be converted to a string again. By introducing this option no IFD is needed for such use-cases, since the fetched files can be assigned directly.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.