* Support a `system' argument for if you want to do hacky things like   change a NixOS installation from x86_64-linux to i686-linux (or vice   versa if you have distributed builds enabled - I used this upgrade   from 32-bit to 64-bit NixOS).
* Support a `system' argument for if you want to do hacky things like
  change a NixOS installation from x86_64-linux to i686-linux (or vice
  versa if you have distributed builds enabled - I used this upgrade
  from 32-bit to 64-bit NixOS).

svn path=/nixos/trunk/; revision=18177

NixOS/nixos,triton/triton,andreassalomonsson/nixos,NixOS/nixos,andreassalomonsson/nixos,andreassalomonsson/nixos,SymbiFlow/nixpkgs,triton/triton,rbvermaa/nixos-svn,andreassalomonsson/nixos,andreassalomonsson/nixos,NixOS/nixpkgs,NixOS/nixpkgs,triton/triton,NixOS/nixos,NixOS/nixos,rbvermaa/nixos-svn,NixOS/nixos,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,triton/triton,edolstra/nixos,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,edolstra/nixos,triton/triton,NixOS/nixpkgs,NixOS/nixpkgs,edolstra/nixos,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,triton/triton,SymbiFlow/nixpkgs,triton/triton,NixOS/nixpkgs,NixOS/nixos,NixOS/nixpkgs,SymbiFlow/nixpkgs,edolstra/nixos,edolstra/nixos,rbvermaa/nixos-svn,andreassalomonsson/nixos,SymbiFlow/nixpkgs,NixOS/nixpkgs,rbvermaa/nixos-svn,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,triton/triton,NixOS/nixpkgs