anchor.diff:  }:
   
   let
  +
     nixpkgs' = nixpkgs; # urgh
   
     pkgs = import <nixpkgs> {};
  
positive.code:     name = "nixos-${nixos.tarball.version}";
      meta = {
        description = "Release-critical builds for the NixOS unstable channel";
        maintainers = [ pkgs.lib.maintainers.shlevy ];
      };
      constituents =
        [ nixos.channel
          nixos.manual
  
          nixos.iso_minimal.x86_64-linux
          nixos.iso_minimal.i686-linux
          nixos.iso_graphical.x86_64-linux
          nixos.iso_graphical.i686-linux
  
          nixos.tests.firefox.x86_64-linux
          nixos.tests.firewall.x86_64-linux
          nixos.tests.installer.lvm.x86_64-linux
          nixos.tests.installer.separateBoot.x86_64-linux
          nixos.tests.installer.simple.i686-linux
          nixos.tests.installer.simple.x86_64-linux
          nixos.tests.kde4.i686-linux
          nixos.tests.login.i686-linux
          nixos.tests.login.x86_64-linux
          nixos.tests.misc.i686-linux
          nixos.tests.misc.x86_64-linux
  
          nixpkgs.tarball
          nixpkgs.emacs.i686-linux
          nixpkgs.emacs.x86_64-linux
        ];
    };
  
  
negative.code:       then set // { meta = builtins.removeAttrs (set.meta or {}) [ "maintainers" ]; }
        else pkgs.lib.mapAttrs (n: v: removeMaintainers v) set
      else set;
  
  in rec {
    nixos = removeMaintainers (import ./release.nix {
      inherit nixosSrc officialRelease;
  