anchor.diff:  
     cmakeFlags = [ "-DCMAKE_BUILD_TYPE=Release" ];
   
  +  postInstall = ''
  +    wrapProgram $out/bin/linja --prefix PATH : $out/bin:${ninja}/bin
  +  '';
  +
     meta = {
       description = "Automatic and interactive theorem prover";
       homepage    = "http://leanprover.github.io";
  
positive.code: { stdenv, fetchFromGitHub, cmake, gmp, mpfr, luajit, boost, python
  , gperftools, ninja }:
  
  stdenv.mkDerivation rec {
    name = "lean-${version}";
  
negative.code:     sha256 = "1gr024bly92kdjky5qvcm96gn86ijakziiyrsz91h643n1iyxhms";
    };
  
    buildInputs = [ gmp mpfr luajit boost cmake python gperftools ninja makeWrapper ];
    enableParallelBuilding = true;
  
    preConfigure = ''
  