anchor.diff:      ++ optional enableAvx512 "--enable-avx512"
       ++ optional enableFma "--enable-fma"
       ++ [ "--enable-openmp" ]
  +    ++ optional enableMpi "--enable-mpi"
       # doc generation causes Fortran wrapper generation which hard-codes gcc
       ++ optional (!withDoc) "--disable-doc";
   
  
positive.code: , enableAvx2 ? stdenv.hostPlatform.avx2Support
  , enableAvx512 ? stdenv.hostPlatform.avx512Support
  , enableFma ? stdenv.hostPlatform.fmaSupport
  }:
  
  with lib;
  
negative.code: 
    nativeBuildInputs = [ gfortran ];
  
    buildInputs = optionals stdenv.cc.isClang [
      # TODO: This may mismatch the LLVM version sin the stdenv, see #79818.
      llvmPackages.openmp
    ] ++ optional enableMpi mpi;
  
    configureFlags =
      [ "--enable-shared"
  