ce416779bb
This avoids a possible surprise if the user is using `nixpkgs.system` and `nesting.children`. `nesting.children` is expected to ignore all parent configuration so we shouldn't propagate the user-facing option `nixpkgs.system`. To avoid doing so, we introduce a new internal option for holding the value passed to eval-config.nix, and use that when recursing for nesting.
*** 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.