anchor.diff: -{ stdenv, fetchFromGitHub, python, gfortran, blas, lapack
  +{ stdenv, fetchFromGitHub, python3, gfortran, blas, lapack
   , fftw, libint2, libxc, mpi, gsl, scalapack, openssh, makeWrapper
   , libxsmm, spglib, which
   , optAVX ? false
  
positive.code: assert (!blas.isILP64) && (!lapack.isILP64);
  
  let
    version = "7.1.0";
  
    cp2kVersion = "psmp";
    arch = "Linux-x86-64-gfortran";
  
negative.code:   enableParallelBuilding = true;
  
    postPatch = ''
      patchShebangs tools exts/dbcsr/tools/build_utils exts/dbcsr/.cp2k
      substituteInPlace exts/dbcsr/.cp2k/Makefile --replace '/usr/bin/env python3' '${python3}/bin/python'
    '';
  
    configurePhase = ''
      cat > arch/${arch}.${cp2kVersion} << EOF
      CC         = mpicc
      CPP        =
      FC         = mpif90
      LD         = mpif90
  