Compiling SFINCS from Source#

SFINCS is included as a Git submodule under coastal_models/sfincs/repo/. The sfincs_run workflow stage requires the sfincs binary to be on PATH (or pointed to via the sfincs_exe config option).

Using Pixi (Recommended)#

SFINCS is built as a pixi-build package using the rattler-build backend. The recipe lives at coastal_models/sfincs/ with three files:

File	Purpose
`pixi.toml`	Package metadata and build backend declaration
`recipe.yaml`	Conda recipe (source path, build/host/run dependencies, tests)
`build.sh`	Build script (autotools configure + make, macOS SDK probe)

Any pixi environment that includes the sfincs feature (sfincs, dev, test311, test313) will automatically build and install the sfincs conda package on first pixi install. Subsequent runs use the cached package and complete instantly (~0.3 s) unless the submodule source or recipe changes.

The binary is installed into the active pixi environment ($CONDA_PREFIX/bin/sfincs), so it is immediately available on PATH when running inside that environment.

Key recipe details#

Source: ./repo/source (the SFINCS autotools tree inside the submodule)
MPI variants: hdf5 and libnetcdf are pinned to mpi_openmpi_* builds so that SFINCS, SCHISM, and ESMF share the same MPI-linked libraries at runtime
macOS SDK probe: scripts/find_compatible_sdk.sh dynamically tests each installed SDK and picks the newest one compatible with conda-forge's linker
Parallel make disabled: SFINCS's Makefile.am has incomplete Fortran module dependency declarations, so the build uses make -j1

Manual Build#

If you prefer to build outside pixi, follow the platform-specific instructions below. The resulting binary has no runtime library dependencies -- just copy it wherever you need it and run.

Ubuntu#

Install Dependencies#

sudo apt update
sudo apt install -y \
  build-essential \
  gfortran \
  autoconf \
  automake \
  libtool \
  m4 \
  pkg-config \
  libnetcdf-dev

Build#

cd coastal_models/sfincs/repo/source

# Generate the configure script (only needed when building from the git repo)
autoreconf -vif

# -fallow-argument-mismatch is needed for netcdf-fortran with GCC >= 10
# see https://github.com/Unidata/netcdf-fortran/issues/212
export FCFLAGS="-fopenmp -O3 -fallow-argument-mismatch -w"
export FFLAGS="-fopenmp -O3 -fallow-argument-mismatch -w"

# Only for older SFINCS versions bundling netcdf-fortran 4.4.4:
# GCC >= 14 errors on implicit function declarations in its configure tests.
# Also need explicit netCDF paths since 4.4.4 doesn't pick them up from pkg-config,
# and parallel make must be disabled (use make -j1) due to missing Fortran module
# dependency declarations in the Makefile.
# export CFLAGS="-Wno-error=implicit-function-declaration"
# export CPPFLAGS="-I$(nc-config --includedir)"
# export LDFLAGS="-L$(nc-config --libdir)"

CC=gcc FC=gfortran ./configure --prefix=$HOME/.local --disable-shared --disable-openacc
make -j1
make install

The statically linked executable is at ~/.local/bin/sfincs. Verify with:

file ~/.local/bin/sfincs   # should show "statically linked"
ldd ~/.local/bin/sfincs    # should print "not a dynamic executable"

macOS#

Note: macOS does not support fully static executables (Apple does not ship static versions of system libraries). The instructions below statically link all non-system libraries (netCDF, HDF5, gfortran runtime, etc.) so the binary is as self-contained as possible.

Install Dependencies#

Install Homebrew if not already present:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install packages:

brew install gcc autoconf automake libtool pkg-config netcdf

Build#

Homebrew installs GCC as versioned commands (gcc-14, gfortran-14, etc.). The snippet below detects the version automatically:

cd coastal_models/sfincs/repo/source
autoreconf -vif

# Detect Homebrew GCC version
GCC_VERSION=$(brew list --versions gcc | grep -oE '[0-9]+' | head -1)

export FCFLAGS="-fopenmp -O3 -fallow-argument-mismatch -w"
export FFLAGS="-fopenmp -O3 -fallow-argument-mismatch -w"

# Enable zstd support in netcdf-fortran (Homebrew netCDF is built with zstd)
export HDF5_PLUGIN_PATH="$(nc-config --plugindir)"

# Only for older SFINCS versions bundling netcdf-fortran 4.4.4:
# GCC >= 14 errors on implicit function declarations in its configure tests.
# Also need explicit netCDF paths since 4.4.4 doesn't pick them up from pkg-config,
# and parallel make must be disabled (use make -j1) due to missing Fortran module
# dependency declarations in the Makefile.
# export CFLAGS="-Wno-error=implicit-function-declaration"
# export CPPFLAGS="-I$(nc-config --includedir)"
# export LDFLAGS="-L$(nc-config --libdir)"

CC=gcc-${GCC_VERSION} FC=gfortran-${GCC_VERSION} \
  ./configure --prefix=$HOME/.local --disable-shared --disable-openacc
make -j1
make install

The executable is at ~/.local/bin/sfincs.

Apple Silicon (M1/M2/M3/M4): Homebrew installs to /opt/homebrew. If pkg-config cannot find netcdf, export the path before running configure:
export PKG_CONFIG_PATH="/opt/homebrew/lib/pkgconfig:$PKG_CONFIG_PATH"

Verifying the Build#

A minimal smoke test is included in the repository:

cd coastal_models/sfincs/repo/source
make test   # runs test/01_noadv

Quick Reference#

Item	Ubuntu	macOS (Homebrew)
Fortran compiler	`gfortran` (via `apt`)	`gfortran` (via `brew install gcc`)
C compiler	`gcc` (via `build-essential`)	`gcc-N` (via `brew install gcc`)
Autotools	`autoconf automake libtool m4`	`autoconf automake libtool`
NetCDF C library	`libnetcdf-dev`	`netcdf`
pkg-config	`pkg-config`	`pkg-config`