anchor.diff:    checkPhase = ''
       runHook preCheck
   
  +    make tests -j $NIX_BUILD_CORES
       ctest -j $NIX_BUILD_CORES --output-on-failure -E smpi-replay-multiple
   
       runHook postCheck
  
positive.code: 
  stdenv.mkDerivation rec {
    name = "simgrid-${version}";
    version = "3.21";
  
    src = fetchFromGitHub {
      owner = "simgrid";
      repo = "simgrid";
      rev = "v${replaceChars ["."] ["_"] version}";
      sha256 = "1v0dwlww2wl56ms8lvg5zwffzbmz3sjzpkqc73f714mrc9g02bxs";
    };
  
    nativeBuildInputs = [ cmake perl python3 boost valgrind ]
  
negative.code:   # - lua53:  for enable_lua
    #
    # For more information see:
    # https://simgrid.org/doc/3.22/Installing_SimGrid.html#simgrid-compilation-options)
    cmakeFlags= ''
      -Denable_documentation=${optionOnOff buildDocumentation}
      -Denable_java=${optionOnOff buildJavaBindings}
  