anchor.diff:    };
     ihaskellDataDir = ihaskellDataDirFunc ihaskellKernelSpec ihaskellLabextension;
   
  -  ihaskellBuildEnvFunc = { ihaskellEnv, jupyterlab, sysPackages, ihaskellDataDir }: nixpkgs.buildEnv {
  +  ihaskellBuildEnvFunc = { ihaskellEnv, jupyterlab, systemPackages, ihaskellDataDir }: nixpkgs.buildEnv {
       name = "ihaskell-with-packages";
       buildInputs = [ nixpkgs.makeWrapper ];
       paths = [ ihaskellEnv jupyterlab ];
  
positive.code:       inherit haskellPackages;
        inherit ihaskellExe;
        inherit ihaskellEnv;
        inherit jupyterlab;
        inherit ihaskellGhcLibFunc;
        inherit ihaskellKernelFileFunc;
        inherit ihaskellKernelSpecFunc;
        inherit ihaskellLabextension;
        inherit ihaskellDataDirFunc;
        inherit ihaskellBuildEnvFunc;
      };
    };
  
    ihaskellBuildEnv = ihaskellBuildEnvFunc {
      inherit ihaskellEnv;
      inherit jupyterlab;
      inherit ihaskellDataDir;
      sysPackages = systemPackages nixpkgs;
    };
  
  in ihaskellBuildEnv
  
negative.code:       for prg in $out/bin"/"*;do
          if [[ -f $prg && -x $prg ]]; then
            wrapProgram $prg \
              --prefix PATH : "${nixpkgs.lib.makeBinPath ([ihaskellEnv] ++ (systemPackages nixpkgs))}" \
              --prefix JUPYTER_PATH : "${ihaskellDataDir}"
          fi
        done
  