anchor.diff:  
     persistent = buildFromGitHub {
       version = 5;
  -    date = "2018-01-27";
  +    date = "2018-03-01";
       owner  = "xiaq";
       repo   = "persistent";
  -    rev = "3d4eb2be76e07dd8cf579c114e2048cbfd540cca";
  -    sha256 = "15kv7nxxi3zbnbalsvx2srykr0zlnhhbmr5mcy4kbg9hx2s5i6zq";
  +    rev = "cd415c64068256386eb46bbbb1e56b461872feed";
  +    sha256 = "1nha332n4n4px21cilixy4y2zjjja79vab03f4hlx08syfyq5yqk";
     };
   
     persistent-cookiejar = buildFromGitHub {
  
positive.code: 
    sys = buildFromGitHub {
      version = 5;
      rev = "88d2dcc510266da9f7f8c7f34e1940716cab5f5c";
      date = "2018-02-23";
      owner  = "golang";
      repo   = "sys";
      sha256 = "1xrps645i71hkq0ljpbk5625d6w7rcb96z59mz0df2lp48mkimj1";
      goPackagePath = "golang.org/x/sys";
    };
  
  
negative.code:   };
  
    bolt = buildFromGitHub {
      version = 5;
      rev = "fd01fc79c553a8e99d512a07e8e0c63d4a3ccfc5";
      owner  = "boltdb";
      repo   = "bolt";
      sha256 = "05ma1sn604hs6smr8alzx6nfzfi289ixxzknj0p73miwdfpz9299";
      buildInputs = [
        sys
      ];
      date = "2018-03-02";
    };
  
    btcd = buildFromGitHub {
  