anchor.diff:  { stdenv, lib, writeText, requireFile, python27, perl, gfortran
  -, openblasCompat, mpi, scalapack
  +, blas, lapack, mpi, scalapack
   # compile the MPI version
   , useMPI ? false
   } :
  +
  +assert (!blas.isILP64) && (!lapack.isILP64);
   
   let
     version = "8.4.17";
  
positive.code:   };
  
    nativeBuildInputs = [ ];
    buildInputs = [ gfortran python27 perl openblasCompat ] ++ lib.optional useMPI [ mpi scalapack ];
  
    postPatch = ''
      patchShebangs ./bin
  
negative.code: 
    configurePhase = ''
      cp ${platformcnf} install/platform.cnf.priv
      sed -i 's/EXTERNAL_BLAS.*/EXTERNAL_BLAS=-lblas/;s/EXTERNAL_LAPACK.*/EXTERNAL_LAPACK=-llapack/' \
           install/compile.cnf_le
  
      mkdir utils
  