anchor.diff:  { lib, buildDunePackage, fetchurl
  -, fmt, mirage-flow, result, rresult, cstruct, logs, ke, lwt
  -, alcotest, alcotest-lwt, bigstringaf, bigarray-compat
  +, fmt, mirage-flow, cstruct, logs, ke, lwt
  +, alcotest, alcotest-lwt, bigstringaf
   }:
   
   buildDunePackage rec {
     pname = "mimic";
     version = "0.0.4";
   
  -  minimumOCamlVersion = "4.08";
  -  useDune2 = true;
  +  minimalOCamlVersion = "4.08";
   
     src = fetchurl {
       url = "https://github.com/dinosaure/mimic/releases/download/${version}/mimic-${version}.tbz";
  
positive.code:     alcotest
      alcotest-lwt
      bigstringaf
      bigarray-compat
      cstruct
      ke
    ];
  
negative.code:     fmt
      lwt
      mirage-flow
      logs
    ];
  
  