Installation

Prerequisites

A Fortran 2003+ compliant compiler is required. The following compilers are known to work:

Compiler	Minimum version
GNU gfortran	14.3+ on the 14 series, or ≥ 15.1
Intel Fortran (ifort / ifx)	≥ 16.x
NVIDIA HPC Fortran (nvfortran)	≥ 26.9 (GPU device build only, see below)

Older gfortran versions

gfortran 13.3 and 14.2 were reported to crash while building the test suite (internal compiler error: in matching_typebound_op, on src/tests/fossil_test_sanitize_normals_strict.f90, see issue #24). The trigger, an associate whose selector is a type-bound operator expression (a gfortran bug, fixed in 14.3 and 15.2), has been removed from the test, which made 15.1 build again. 13.3 and 14.2 should now build too, but they are not tested. Verified versions:

gfortran	Result
13.3, 14.2	internal compiler error before the workaround; not retested
14.3	builds, all tests pass (CI)
15.1, 15.2, 16.2	builds, all tests pass

The NVIDIA modes (static-nvidia, tests-nvidia) build the OpenACC GPU distance path; tests-nvidia builds only the distance benchmark, not the full test suite.

FOSSIL is developed on GNU/Linux. Windows should work but is not officially tested.

Download

git clone https://github.com/szaghi/FOSSIL
cd FOSSIL
fobis fetch

FOSSIL's third-party dependencies are not git submodules. They are declared in the [dependencies] section of fobos and fetched into src/third_party/ by fobis fetch (pinned in src/third_party/fobos.lock). fobis fetch --update re-fetches them. fpm users need neither step: fpm resolves the same dependencies from fpm.toml.

Third-Party Dependencies

Fetched into src/third_party/:

Library	Purpose
PENF	Portable numeric kind parameters (I4P, R8P, etc.)
VecFor	3D vector type and operations (vector_R8P, unit vectors, rotation/mirror matrices)
FLAP	Fortran command-line argument parser (used by fossilizer)
FACE	ANSI terminal color/style support
BeFoR64	Base64 encoding
FoXy	XML/XDMF support
StringiFor	String utilities
VTKFortran	VTK file I/O

Build with FoBiS.py

FoBiS.py is the primary build system. Install once with pip — the PyPI package name is FoBiS.py; the installed CLI binary is fobis:

pip install FoBiS.py

List all build modes

fobis build --lmodes

Available modes:

Mode	Description
static-gnu	Static library with gfortran (release)
shared-gnu	Shared library with gfortran (release)
static-gnu-debug	Static library with gfortran (debug + checks)
shared-gnu-debug	Shared library with gfortran (debug)
tests-gnu	Build all tests with gfortran (release)
tests-gnu-openmp	Build all tests with gfortran + OpenMP (distance_many threaded)
tests-gnu-debug	Build all tests with gfortran (debug)
static-intel	Static library with ifort (release)
shared-intel	Shared library with ifort (release)
static-intel-debug	Static library with ifort (debug)
shared-intel-debug	Shared library with ifort (debug)
tests-intel	Build all tests with ifort (release)
tests-intel-debug	Build all tests with ifort (debug)
static-nvidia	Static library with nvfortran + OpenACC (GPU, needs --varset local_nvf)
tests-nvidia	GPU distance benchmark only, with nvfortran + OpenACC (needs --varset local_nvf)

Build the library

# Static library (GNU gfortran)
fobis build --mode static-gnu

# Shared library (GNU gfortran)
fobis build --mode shared-gnu

# Static library (Intel Fortran)
fobis build --mode static-intel

The library is placed in ./static/ or ./shared/ respectively, with its module files in mod/ under the same directory (e.g. ./static/mod/).

Build and run tests

fobis build --mode tests-gnu
./scripts/run_tests.sh

Compiled test executables are placed in ./exe/. Each test prints "Are all tests passed? T" on success.

To run a single test:

./exe/fossil_test_clip

Coverage and documentation

fobis rule --ex makecoverage   # build + run tests + gcov report
fobis rule --ex makedoc        # build formal API docs + VitePress site

Build with fpm

fpm build --profile release

fpm resolves the dependencies declared in fpm.toml; no fobis fetch is needed.

FOSSIL ships no CMake or Make build files: scripts/install.sh --build cmake|make skips the build with a warning. Use --build fobis or --build fpm.