anchor.diff:  
     raven-go = buildFromGitHub {
       rev    = "74c334d7b8aaa4fd1b4fc6aa428c36fed1699e28";
  -    date   = "2015-07-21";
  +    version = "2015-07-21";
       owner  = "getsentry";
       repo   = "raven-go";
       sha256 = "1356a7h8zp1mcywnr0y83w0h4qdblp65rcf9slbx667n8x2rzda8";
  
positive.code: 
    go-lxc = buildFromGitHub {
      rev    = "d89df0ad9dc13a7ce491eedaa771b076cf32db16";
      date   = "2016-02-12";
      owner  = "lxc";
      repo   = "go-lxc";
      sha256 = "051kqvvclfcinqcbi4zch694llvnxa5vvbw6cbdxbkzhr5zxm36q";
  
negative.code: 
    prometheus.client_model = buildFromGitHub {
      rev    = "fa8ad6fec33561be4280a8f0514318c79d7f6cb6";
      version = "2015-02-12";
      owner  = "prometheus";
      repo   = "client_model";
      sha256 = "11a7v1fjzhhwsl128znjcf5v7v6129xjgkdpym2lial4lac1dhm9";
  