my $class = Module::Build->subclass
  (
   class => 'My::Builder',
   code => q#
    sub make_parfile {
      my ($self, $file) = @_;
      $file =~ s/(?<!\.par)$/.par/;
      print "Creating $file\n";
      require Archive::Zip;
      my $zip = Archive::Zip->new();
      $zip->addFile($_) for keys %{ $self->_read_manifest('MANIFEST') };
      die 'write error' unless $zip->writeToFileNamed( $file ) == Archive::Zip->AZ_OK;
    }
    sub ACTION_pardist {
      my($self) = @_;
      $self->make_parfile(join "-", $self->dist_name, $self->dist_version);
    }
   #,
  );

my $build = $class->new

# The rest is the same.