This is a major release of DOLFINx and users are advised to upgrade.

A curated set of release notes is available at: https://fenicsproject.org/blog/v0.9.0/

What's Changed

Features and API changes

• Add support for mixed-domain problems of codimension 1 by @jpdean in #3224
• Interpolation to and from sub-meshes for co-dimension 0 by @jorgensd in #3114
• Favor exterior_facet_indices over locate_entities_boundary for retrieving complete boundary by @schnellerhase in #3283
• Add specific HPC install recommendation by @jhale in #3161
• Updates and clarifications in release notes by @jhale in #3160
• Interpolation into symmetric tensor by @mscroggs in #3158
• Support Python interface build and run without petsc4py by @garth-wells in #3182
• Split PETSc and non-PETSc tests on CI by @garth-wells in #3184
• Allow for symmetric quadrature elements by @mscroggs in #3188
• Make standalone function for interpolation over non-matching meshes by @jorgensd in #3177
• Add pyamg demo by @chrisrichardson in #3202
• Switch to spdlog by @chrisrichardson in #3216
• Expose interpolation matrix for MatrixCSR (without PETSc) by @chrisrichardson in #3226
• Support mixed topology for dual graph by @chrisrichardson in #3234
• Allow dx and dx(i) in same form by @jorgensd in #3253
• Enable SCOTCH detection via CMake CONFIG mode. by @garth-wells in #3244
• Port DOLFINx to Windows by @jhale in #3198
• Generalize all output formats for general length vectors and tensors by @jorgensd in #3227
• Prepare for release of numpy 2.0 by using ruff ruleset by @jorgensd in #3261
• Export missing compile time constants to python by @schnellerhase in #3285
• One dimensional refinement routine by @schnellerhase in #3314
• Extend to_dense for parallel use cases by @schnellerhase in #3354
• Clarify memory management of returned petsc4py objects. by @jhale in #3329
• Remove dictionary from constructor by @jorgensd in #3370
• Sparsity pattern insert by @schnellerhase in #3338
• Timer interface improvement by @schnellerhase in #3328
• Expose Newton convergence check setter in Python by @jorgensd in #3386
• Expose more optional feature booleans, remove Timer from top level dolfinx by @jhale in #3335
• Expose DirichletBC.dof_indices to Python interface by @jorgensd in #3389
• Fix element name in mixed Poisson demo by @jpdean in #3391
• Add Python-interface for geometry constructor and geometry class by @jorgensd in #3403
• Remove NBX call from sub-IndexMap creation by @jorgensd in #3392
• Remove deprecated method for accessing PETSc Vec in Python by @garth-wells in #3435
• Create topology Python wrapper by @jorgensd in #3406
• Add codim_0_assembly demo to CMake by @garth-wells in #3436
• Simplify blocked demos using extract_blocks by @jorgensd in #3450
• Updating demo_axis.py and demo_pml.py for parallel computing by @jorgensd in #3433
• Vertex submesh support by @jorgensd in #3455
• Pass graph partitioner to mesh::refine by @garth-wells in #3444
• Return source rank for each node in constant degree adjacency list when distributing by @garth-wells in #3447
• Use std::optional to reduce code duplication in boundary condition setting by @garth-wells in #3434
• Send multiple cell types to partitioner by @chrisrichardson in #3237
• Data independent form compilation for Python interface by @jorgensd in #3263
• Skip negative cell indices when packing coefficients by @jorgensd in #3361
• Add ARM VTK to Docker Notebook image. by @jhale in #3259

Other changes

• Lint. by @jhale in #3157
• More updates for RELEASE.md by @jhale in #3166
• Lint. by @jhale in #3168
• Try tests on GitHub Actions with three MPI ranks by @jhale in #3163
• Remove dynamic memory allocation inside tight loops in the Plaza refinement code by @garth-wells in #3151
• Bump ADIOS2 version in Dockerfiles by @garth-wells in #3170
• Update versions. by @jhale in #3171
• TST: avoid unused variable in assert by @minrk in #3175
• Do CI linting in Actions image by @garth-wells in #3176
• Reuse Basix element instead of recreating from generated code by @mscroggs in #3136
• Use std::conditional_t for better C++ compatibility by @chrisrichardson in #3183
• Run Actions with OpenMPI and MPICH, and remove CircleCI config by @garth-wells in #3185
• Remove CircleCI badge from README.md by @garth-wells in #3189
• Add check of element hash by @mscroggs in #3186
• Fix reference counting for KSP from NewtonSolver in Python by @garth-wells in #3190
• Update Docker base images to ubuntu:24.04 by @garth-wells in #3192
• Fix patch level for HDF in Dockerfile by @garth-wells in #3193
• Spack ci update by @garth-wells in #3194
• Add break system packages by @jhale in #3196
• Add petsc4py build requirements by @garth-wells in #3197
• Bump Python version in complex kernel to 3.12 by @jorgensd in #3199
• Spack Actions CI update by @garth-wells in #3203
• Simplify oneAPI and Rocky images by @garth-wells in #3205
• Exit demos that require PETSc when PETSc is not available by @garth-wells in #3206
• Simplify oneAPI CI by @garth-wells in #3210
• Add spdlog to doc install requirements by @garth-wells in #3217
• Remove spdlog install from CI yaml by @garth-wells in #3218
• Orient mesh entities consistently and generalise entities_to_geometry by @jpdean in #3209
• Install unzip package in CI for Spack by @garth-wells in #3220
• Improvements and fixes for C++ Doxygen/breathe/sphinx doc processing by @garth-wells in #3221
• Improve documentation for pyamg demo by @chrisrichardson in #3222
• Permutation computation refactoring by @chrisrichardson in #3223
• Change IR to be compatile with UFCx from FFCX PR-680 by @jorgensd in #3137
• Add docstrings to submesh creation in Python interface by @jorgensd in #3112
• Doc fixes and Doxygen version update by @garth-wells in #3228
• Replace nb::any with -1 and add argument to nb::ndarray in preparation of next nanobind release by @francesco-ballarin in #3105
• Clean up Docker files (first step) by @garth-wells in #3230
• Docker simplify (phase 2) by @garth-wells in #3232
• Dockerfile end-user updates by @garth-wells in #3235
• Bump dependency versions in Dockerfile by @garth-wells in #3239
• demo test: default mpiexec to mpiexec by @minrk in #3242
• Distribute fixed width data by @chrisrichardson in #3240
• Simplify integration domain packing by @jorgensd in #3215
• Add dependabot for github actions by @jorgensd in #3245
• Bump actions/setup-python from 2 to 5 by @dependabot in #3247
• Bump docker/login-action from 2 to 3 by @dependabot in #3249
• Bump actions/cache from 3 to 4 by @dependabot in #3250
• Bump actions/github-script from 6 to 7 by @dependabot in #3248
• Temporarily disable Windows CI - upstream issue. by @jhale in #3251
• Small Basix type updates by @garth-wells in #3254
• Make compile time options compile time constants by @schnellerhase in #3246
• Update defines.h by @jhale in #3255
• Add indices of missing connectivity in error message by @garth-wells in #3264
• Use enabled_coefficients to restrict packing of coefficients by @jorgensd in #3260
• Remove .mailmap by @nate-sime in #3266
• Improve error message by @garth-wells in #3267
• Add more output to errors raised on PETSc lib import. by @jhale in #3268
• Pin nanobind version in Spack CI test by @garth-wells in #3270
• Workaround for numpy 2.0 issue with pyamg by @chrisrichardson in #3274
• Create mixed topology mesh by @chrisrichardson in #3271
• MacOS CI fixes by @chrisrichardson in #3277
• Fix pyvista actions by @chrisrichardson in #3276
• Pyamg test Add xfail for now by @chrisrichardson in #3284
• Bump docker/build-push-action from 5 to 6 by @dependabot in #3279
• Improve check for facet->cell connectivity by @chrisrichardson in #3281
• Remove workarounds following upstream updates for CI by @chrisrichardson in #3289
• Set C++ standard using modern cmake by @jhale in #3305
• Replace std::sort with std::ranges::sort by @schnellerhase in #3293
• Replace std::fill with std::ranges::fill by @schnellerhase in #3294
• Replace std::lower/uper_bound with std::ranges::lower/uper_bound by @schnellerhase in #3295
• Replace std::for_each with std::ranges::for_each by @schnellerhase in #3296
• Replace std::min/max with std::ranges::min/max by @schnellerhase in #3300
• Replace std::set_* with std::ranges::set_* by @schnellerhase in #3298
• Replace std::copy with std::ranges::copy by @schnellerhase in #3299
• Fix STL includes by @garth-wells in #3309
• Put gfortran back on PATH for MacOS CI by @chrisrichardson in #3310
• Set CMake policy to avoid warning with newer CMake versions by @garth-wells in #3308
• Only try to lift boundary conditions if forms are provided by @jpdean in #3302
• Replace std::transform with std::ranges::transform by @schnellerhase in #3297
• Restore oneAPI CI by @garth-wells in #3319
• Re-enable Windows CI. by @jhale in #3320
• Replace std::unique with std::ranges::unique by @schnellerhase in #3315
• Rework radix_sort by @schnellerhase in #3313
• Fix comment in prior PR by @schnellerhase in #3323
• Fix bug in interval refinement test by @schnellerhase in #3331
• Fix ubuntu CI by @schnellerhase in #3339
• Turns search for KaHiP on by default. by @jhale in #3337
• General tidy and restrict cffi < 1.17 due to static condensation demo issue by @jhale in #3343
• Fix ruff check by @schnellerhase in #3349
• Try to get OneAPI CI working again by @chrisrichardson in #3350
• Fix bug in create_functionspace by @schnellerhase in #3355
• Fix DofMap::collapse() on rank with no dofs by @jorgensd in #3369
• Fix refine constructor (currently overwriting ufl_cargo) by @jorgensd in #3367
• Fix block vector assembly for mixed-domain problems by @jpdean in #3346
• Mixed dimension assembly in C++ and form independence for subdomains by @jorgensd in #3262
• Reduce complexity of create_submap_indices by @jorgensd in #3378
• Skip test if adios2 python module built without MPI. by @jhale in #3124
• Run macos CI on pull requests by @garth-wells in #3381
• Windows CI on dispatch only by @garth-wells in #3388
• Correct reference value size by @jorgensd in #3373
• Some updates for mesh generation by @schnellerhase in #3275
• Test PETSc solver wrappers by @jorgensd in #3383
• Add read option of prims/wedges through xdmffile by @jorgensd in #3384
• Extend testing of quadrature element by @jorgensd in #3382
• Add error handling of ASCII + write/append mode with XDMFFile. by @jorgensd in #3385
• Check optional features are found/not found. by @jhale in #3390
• Bump dependency version in Dockerfiles by @garth-wells in #3394
• Avoid CMake Boost policy warning by @garth-wells in #3395
• Fix missing template type in generation by @schnellerhase in #3404
• Add interval mesh generation testing by @schnellerhase in #3359
• Fix nanobinding for interprocess facets by @jorgensd in #3405
• Bumping sonar-scanner-cli and removing deprecated command by @jorgensd in #3402
• Unify refine interface by @schnellerhase in #3322
• Expose geometry constructor in Python by @jorgensd in #3400
• Add previously missed refine doc string by @schnellerhase in #3410
• Add/extend refinement testing by @schnellerhase in #3360
• Remove std::map from scatter_values in nonmatching interpolation by @jorgensd in #3396
• Fix docs of facet permutations by @mscroggs in #3412
• Add missing docs regarding diagonal by @jorgensd in #3397
• Remove note about FFCx generated elements by @jorgensd in #3414
• Add CMAKE_PREFIX_PATH to Dockerfile by @jhale in #3416
• Fix cffi_utils for abscence of petsc4py by @schnellerhase in #3415
• Save FFI module in fem form. by @bpachev in #3399
• Fix Python wrapper of distribute_entity_data by @jorgensd in #3421
• A form can be empty and should return None by @jorgensd in #3422
• Document compute_midpoints and remove outdated fixme. by @jorgensd in #3419
• Expose Topology in sphinx docs by @jorgensd in #3423
• Fix argument block-size in Expressions by @jorgensd in #3429
• Fix integer overflow bug in sub-IndexMap extraction by @garth-wells in #3431
• Update Install instructions by @jhale in #3427
• Fix mesh constructor again by @jorgensd in #3432
• Remove outdated demo by @chrisrichardson in #3440
• Check for interprocess facets when assembling interior facet integrals by @jorgensd in #3439
• Remove commented line by @jorgensd in #3441
• Bump PETSC release by @jorgensd in #3445
• Use earlier NumPy version in Dockerfile by @garth-wells in #3448
• Add comment in pyproject.toml on cffi version pin by @garth-wells in #3449
• Move to py311 for oneAPI test by @garth-wells in #3451
• Fix bug in distribute by @chrisrichardson in #3453
• Fix codim-1 assembly on interior facets by @jorgensd in #3452
• Fix arity order of operators in test by @jorgensd in #3458

New Contributors

• @dependabot made their first contribution in #3247
• @schnellerhase made their first contribution in #3246
• @bpachev made their first contribution in #3399

Full Changelog: v0.8.0...v0.9.0