anchor.diff:      };
       meta = {
         description = "assert that code does not cause growth in memory usage";
  +      license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];
  +    };
  +  };
  +
  +  TestMetricsAny = buildPerlModule {
  +    pname = "Test-Metrics-Any";
  +    version = "0.01";
  +    src = fetchurl {
  +      url = mirror://cpan/authors/id/P/PE/PEVANS/Test-Metrics-Any-0.01.tar.gz;
  +      sha256 = "0s744lv997g1wr4i4vg1d7zpzjfw334hdy45215jf6xj9s6wh1i5";
  +    };
  +    propagatedBuildInputs = [ MetricsAny ];
  +    meta = {
  +      description = "assert that code produces metrics via L<Metrics::Any>";
         license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];
       };
     };
  
positive.code:     };
    };
  
    # TODO: use CPAN version
    MHonArc = buildPerlPackage rec {
      pname = "MHonArc";
  
negative.code: 
    IOAsync = buildPerlModule {
      pname = "IO-Async";
      version = "0.77";
      src = fetchurl {
        url = mirror://cpan/authors/id/P/PE/PEVANS/IO-Async-0.77.tar.gz;
        sha256 = "153rfnbs2xwvx559h0ilfr0g9pg30avjad3cad659is9bdmfipri";
      };
      propagatedBuildInputs = [ Future StructDumb ];
      buildInputs = [ TestFatal TestIdentity TestMetricsAny TestRefcount ];
      meta = {
        description = "Asynchronous event-driven programming";
        license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];
  