anchor.diff:    };
   
     mongo-tools = buildFromGitHub {
  -    rev = "r3.3.4";
  +    rev = "0.0.0";
       owner  = "mongodb";
       repo   = "mongo-tools";
       sha256 = "1fc76efb1bee6de51a5c7cb42ff95c09244e3f77f191e1540c9cfe6275608a9c";
  
positive.code:   };
  
    go-isatty = buildFromGitHub {
      rev = "v0.0.1";
      owner  = "mattn";
      repo   = "go-isatty";
      sha256 = "0nknr0wwyclyasrjgbrwkdjrjpjvlm6p7y8df5gqc305bjbfykd8";
    };
  
    go-jmespath = buildFromGitHub {
      rev = "0.2.2";
      owner = "jmespath";
      repo = "go-jmespath";
      sha256 = "0kvwbxxfrji36isgjnqcg73f1dzc61l4r6pcn4r8x42nn1mfpnly";
    };
  
    go-jose = buildFromGitHub {
      rev = "v1.0.1";
      owner = "square";
      repo = "go-jose";
      sha256 = "0pnr0rv2zbsq0dfybg2rqcfnzq0rci9lv8h0dnygs2kgq80yznpl";
  
negative.code: 
    go-immutable-radix = buildFromGitHub {
      date = "2016-02-21";
      rev = "0.0.0";
      owner = "hashicorp";
      repo = "go-immutable-radix";
      sha256 = "0x690ci5pv29v4vma0z1f6qwcffx13n5nqckidhd6irqaf8ylkby";
  