anchor.diff:  let
     toolsOnly = suffix == "tools";
   
  -  inherit (stdenv.lib)
  +  inherit (lib)
       optionals
       optionalString;
   
  
positive.code: { stdenv
  , fetchurl
  , libtool
  , dhcp
  , docbook-xsl-ns
  
negative.code:     };
    };
  
    meta = with lib; {
      homepage = "http://www.isc.org/software/bind";
      description = "Domain name server";
      license = licenses.isc;
  