FEniCS Spack packages overlay repository

This Spack package repository contains Spack packages only for the FEniCS Project components. Using spack repo add it can be overlaid onto any complete upstream package repository. Its FEniCS component package will then take precedence over the upstream package repository.

Instructions

For full instructions on using spack repo see the Spack documentation.

TL;DR on a system with spack installed:

spack repo add https://github.com/FEniCS/spack-fenics.git
spack repo list

Alternatively, to work with this repository:

spack repo list

You should see the builtin repository which points at a folder containing the complete upstream Spack packages repository, e.g.:

[+] builtin    v2.2    /Users/jack.hale/.spack/package_repos/fncqgg4/repos/spack_repo/builtin

Clone this repository:

git clone https://github.com/FEniCS/spack-fenics.git

And add it as a repository:

spack repo add spack-fenics/spack_repo/fenics

Run spack repo list again to show, e.g.:

[+] fenics     v2.4    /Users/jack.hale/fenicsx-main/src/spack-fenics/spack_repo/fenics
[+] builtin    v2.2    /Users/jack.hale/.spack/package_repos/fncqgg4/repos/spack_repo/builtin

Package definitions in fenics will now take precedence over duplicates in builtin.

Running spack spec -N fenics-dolfinx@0.9 should give, e.g.:

 -   fenics.fenics-dolfinx@0.9.0~adios2~ipo~petsc~slepc build_system=cmake build_type=RelWithDebInfo generator=make partitioners:=parmetis platform=darwin os=sequoia target=m1 %c,cxx=apple-clang@17.0.0
...

where fenics.fenics-dolfinx implies the use of the fenics repository.

Maintenance commitment

We aim to keep the last three x versions 0.x.* of py-fenics-dolfinx building with PETSc, SLEPc, ADIOS2, Parmetis, SCOTCH and KaHIP support using Ubuntu LTS-provided GCC and clang. Due to an identified performance issue we are currently not running the test suite for py-fenics-dolfinx@0.8.

Uses

1. Releasing Spack packages to users without waiting for PRs to be merged into the upstream builtin repository.
2. Allows experimentation with FEniCS Spack packages without having to maintain a full branch of the upstream builtin repository.

Observations

C++ ABIs

We have observed issues when two different compilers are selected by Spack to build C++ components. This can lead to missing symbols at runtime error due to different name mangling conventions and application binary interfaces (ABIs). If this happens you can push the compiler down the Spack concretisation using %%, e.g.:

spack spec -N py-fenics-dolfinx %%clang@18

or a more precise approach using ^ and %, e.g.:

spack spec -N py-fenics-dolfinx %clang@18 ^fenics-dolfinx %clang@18 ^py-fenics-basix %clang@18 ^fenics-basix %clang@18

Reproducing complex build environment

To build C++ applications using Spack's build environment (e.g. when it used special compilers to build fenics-dolfinx):

spack load cmake fenics-dolfinx py-fenics-ffcx
spack build-spec --dump spack-build-env.sh fenics-dolfinx
source spack-build-env.sh
# Execute e.g. cmake, should use Spack's compiler-wrapper 

Developer notes

Diffing against an upstream builtin package set:

export OTHER_PACKAGES_DIR=/path/to/spack-packages/repos/spack_repo/builtin/packages 
cd spack-fenics/spack_repo/fenics/package
for dir in */; do; git --no-pager diff --no-index $OTHER_PACKAGES_DIR/$dir $dir; done;