anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "sundials";
  -  version = "5.7.0";
  +  version = "6.2.0";
   
     outputs = [ "out" "examples" ];
   
     src = fetchurl {
       url = "https://github.com/LLNL/sundials/releases/download/v${version}/sundials-${version}.tar.gz";
  -    hash = "sha256-SNp7qoFS3bIq7RsC2C0du0+/6iKs9nY0ARqgMDoQCkM=";
  +    hash = "sha256-GV1Vk3cvxIP2Pwh5TXnkurMMLsWObOSw+2vMDgxI8x0=";
     };
   
  -  nativeBuildInputs = [ cmake gfortran ];
  +  nativeBuildInputs = [
  +    cmake
  +    gfortran
  +  ];
   
     buildInputs = [
       python
  
positive.code: 
    meta = with lib; {
      description = "Suite of nonlinear differential/algebraic equation solvers";
      homepage    = "https://computation.llnl.gov/projects/sundials";
      platforms   = platforms.all;
      maintainers = with maintainers; [ idontgetoutmuch ];
      license     = licenses.bsd3;
  
negative.code:       blas
        lapack
      ])
    # KLU support is based on Suitesparse. It is tested upstream according to the
    # section 1.1.4.2 of INSTALL_GUIDE.pdf found in the source tarball.
    ++ lib.optionals (kluSupport) [
      suitesparse
    ];
  