anchor.diff:      "SHARED_MODE=1"
     ];
   
  -  passthru = {
  -    inherit version;
  -  };
  -
     meta = with lib; {
       homepage = "https://zlib.net";
       description = "Lossless data-compression library";
       license = licenses.zlib;
       platforms = platforms.all;
     };
  -} // lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform) {
  -  preConfigure = ''
  -    export CHOST=${stdenv.hostPlatform.config}
  -  '';
  -} // lib.optionalAttrs (stdenv.hostPlatform.libc == "msvcrt") {
  -  dontConfigure = true;
  -})
  +}
  
positive.code:     ++ lib.optional splitStaticOutput "static";
    setOutputFlags = false;
    outputDoc = "dev"; # single tiny man3 page
  
    # For zlib's ./configure (as of verion 1.2.11), the order
    # of --static/--shared flags matters!
  
negative.code: 
  assert splitStaticOutput -> static;
  
  stdenv.mkDerivation rec {
    pname = "zlib";
    version = "1.2.12";
  
  