anchor.diff:    ] ++ lib.optionals withBlas [
       openblas
     ];
  +
     propagatedBuildInputs = [
       mpfr # flint.h includes mpfr.h
     ];
  +
     configureFlags = [
       "--with-gmp=${gmp}"
       "--with-mpir=${mpir}"
  
positive.code: { lib, stdenv
  , fetchurl
  , gmp
  , mpir
  
negative.code:   version = "2.8.0";
  
    src = fetchurl {
      url = "https://www.flintlib.org/flint-${version}.tar.gz";
      sha256 = "sha256-WEI1zcOdd52ZIOrvFv4ITzwm/+7qADo//2SiCg8zRJ4=";
    };
  
  