{
  stdenv
, mpi ? null
, tampi ? null
, mcxx ? null
, cc
, gitBranch
}:

with stdenv.lib;

assert !(tampi != null && mcxx == null);

stdenv.mkDerivation rec {
  name = "fwi";

  src = builtins.fetchGit {
    url = "https://gitlab.com/srodrb/BSC-FWI.git";
    ref = "${gitBranch}";
  };

  enableParallelBuilding = true;

  buildInputs = [
    cc
  ]
  ++ optional (mpi != null) mpi
  ++ optional (tampi != null) tampi
  ++ optional (mcxx != null) mcxx;

  # FIXME: This is an ugly hack.
  # When using _GNU_SOURCE or any other definition used in features.h, we need
  # to define them before mcc includes nanos6.h from the command line. So the
  # only chance is by setting it at the command line with -D. Using the DEFINES
  # below, reaches the command line of the preprocessing stage with gcc.
  preConfigure = ''
    export DEFINES=-D_GNU_SOURCE
    export NANOS6_CONFIG_OVERRIDE=version.debug=true
  '';
  
  # We compile the ModelGenerator using gcc *only*, as otherwise it will
  # be compiled with nanos6, which requires access to /sys to determine
  # hardware capabilities. So it will fail in the nix-build environment,
  # as there is no /sys mounted.
  preBuild = ''
    make COMPILER=GNU ModelGenerator
  '';

  makeFlags = [
    "CC=${cc.cc.CC}"
  ];

  postBuild = ''
    make input
  '';

  #FIXME split the input in another derivation
  installPhase = ''
    mkdir -p $out/bin
    cp fwi $out/bin
    cp ModelGenerator $out/bin
    mv InputModels $out/bin
    mkdir -p $out/etc/fwi
    cp SetupParams/{fwi_frequencies.txt,fwi_params.txt} $out/etc/fwi
  '';

  programPath = "/bin/fwi";
}