anchor.diff:      ln -sv . "$incdir"
     '';
   
  -  meta = with stdenv.lib; {
  +  meta = with lib; {
       maintainers = with maintainers; [
         wkennington
       ];
  
positive.code: { stdenv
  , fetchurl
  , perl
  }:
  
  let
    version = "1.9.2";
  in
  stdenv.mkDerivation rec {
    name = "libbson-${version}";
  
negative.code:   src = fetchurl {
      url = "https://github.com/mongodb/libbson/releases/download"
        + "/${version}/${name}.tar.gz";
      sha256 = "244e786c746fe6326433b1a6fcaadbdedc0da3d11c7b3168f0afa468f310e5f1";
    };
  
    nativeBuildInputs = [
  