anchor.diff:        inherit fetchurl stdenv perl curl bzip2 openssl bison;
         inherit libtool automake autoconf docbook5 docbook5_xsl libxslt docbook_xml_dtd_43 w3m;
   
  -      aterm = aterm242fixes;
  +      aterm = aterm25;
         db4 = db45;
   
         flex = flex2533;
  
positive.code: 
    nix = makeOverridable (import ../tools/package-management/nix) {
      inherit fetchurl stdenv perl curl bzip2 openssl;
      aterm = aterm242fixes;
      db4 = db45;
      supportOldDBs = getPkgConfig "nix" "OldDBSupport" true;
      storeDir = getPkgConfig "nix" "storeDir" "/nix/store";
  
negative.code:   # The bleeding edge.
    nixUnstable = makeOverridable (import ../tools/package-management/nix/unstable.nix) {
      inherit fetchurl stdenv perl curl bzip2 openssl;
      aterm = aterm25;
      storeDir = getPkgConfig "nix" "storeDir" "/nix/store";
      stateDir = getPkgConfig "nix" "stateDir" "/nix/var";
    };
  