anchor.diff:  
   buildGoModule rec {
     pname = "age";
  -  version = "unstable-2020-03-25";
  +  version = "1.0.0-beta4";
     goPackagePath = "github.com/FiloSottile/age";
     vendorSha256 = "0km7a2826j3fk2nrkmgc990chrkcfz006wfw14yilsa4p2hmfl7m";
   
  
positive.code:   src = fetchFromGitHub {
      owner = "FiloSottile";
      repo = "age";
      rev = "f0f8092d60bb96737fa096c29ec6d8adb5810390";
      sha256 = "079kfc8d1pr39hr4qnx48kviyzwg4p8m4pz0bdkypns4aq8ppbfk";
    };
  
    meta = with lib; {
  
negative.code:     license = licenses.bsd3;
      maintainers = with maintainers; [ tazjin ];
    };
  }
  