
In general, you don't want a .tar.gz file to be served with "Content-Encoding: x-gzip", because this causes browsers (like Chrome or "curl --compressed") to decompress the file on the fly. So you end up with a .tar rather than .tar.gz file, which is unexpected. If people want such encodings, they should set them in their own NixOS configuration.
*** 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.