anchor.diff:  
     staging = fetchFromGitHub rec {
       inherit (unstable) version;
  -    sha256 = "1xx9bfirij12l278f5f7vpxxay1zacnrsaib6yfzrybm517ynfw3";
  +    sha256 = "1nk8s54nrlws0d8wpyj1vv2z0l2jansn990xw73v15wzwc3j9p6l";
       owner = "wine-compholio";
       repo = "wine-staging";
       rev = "v${version}";
     };
   
     winetricks = fetchFromGitHub rec {
  -    version = "20160724";
  -    sha256 = "0nl8gnmsqwwrc8773q8py64kv3r5836xjxsnxjv91n4hhmvgyrzs";
  +    version = "20170101";
  +    sha256 = "0c2aam68x3nlvc6f4r6rnfw6y3a86644zb0qirwkmh3p04mpdl39";
       owner = "Winetricks";
       repo = "winetricks";
       rev = version;
  
positive.code: in rec {
  
    stable = fetchurl rec {
      version = "1.8.4";
      url = "https://dl.winehq.org/wine/source/1.8/wine-${version}.tar.bz2";
      sha256 = "0yahh1n3s3y0bp1a1sr3zpna56749jdgr85hwmpq393pjx1i0pai";
  
      ## see http://wiki.winehq.org/Gecko
      gecko32 = fetchurl rec {
  
negative.code:   };
  
    unstable = fetchurl rec {
      version = "2.0-rc3";
      url = "https://dl.winehq.org/wine/source/2.0/wine-${version}.tar.bz2";
      sha256 = "0sq8li7p30h2a5bbpv27vxpzihr8h890qm78nq21fnh0zflg8x8y";
      inherit (stable) mono;
      gecko32 = fetchurl rec {
        version = "2.47";
  