anchor.diff: -{ lib, stdenv, makeWrapper, buildEnv,
  -  breezy, coreutils, cvs, findutils, gawk, git, gnused, mercurial, nix, subversion
  +{ lib, stdenv, makeWrapper, buildEnv
  +, breezy, coreutils, cvs, findutils, gawk, git, gnused, mercurial, nix, subversion
   }:
   
   let mkPrefetchScript = tool: src: deps:
  
positive.code:     meta = with lib; {
        description = "Script used to obtain source hashes for fetch${tool}";
        maintainers = with maintainers; [ bennofs ];
        platforms = lib.platforms.unix;
      };
    };
  in rec {
  
negative.code:     meta = with lib; {
        description = "Collection of all the nix-prefetch-* scripts which may be used to obtain source hashes";
        maintainers = with maintainers; [ bennofs ];
        platforms = platforms.unix;
      };
    };
  }
  