New macOS deal.II packages (arm64, clang-17) now available

[Luca Heltai]

Hi all,

after a bit of testing and fighting with compilation issues, I’m happy to share two freshly built deal.II bundles for Apple Silicon, compiled with clang-17 and packaged as native macOS apps:

- dealii-9.7.1-tahoe-arm64-clang17.dmg (optimized for macOS 26 “Tahoe” toolchain)

https://github.com/dealii/dealii/releases/download/v9.7.1/dealii-9.7.1-tahoe-arm64-clang17.dmg

- dealii-9.7.1-sequoia-arm64-clang17.dmg (optimized for macOS 15 “Sequoia” toolchain)

https://github.com/dealii/dealii/releases/download/v9.7.1/dealii-9.7.1-sequoia-arm64-clang17.dmg


Both images contain:
- deal.II 9.7.1 built for arm64 (no Rosetta required)
- all supported (stable) software stack (MPI, Trilinos, PETSc/SLEPc, p4est, SuiteSparse, HDF5, VTK, CGAL, etc.)

Both images require the user to install the xcode-select command line tools (for apple-clang 17 toolchain), and contain a full spack and brew installation. Brew is used only for the gcc/gfortran compiler.

Quick start:
- Open the DMG and drag deal.II.app to /Applications
- Launch deal.II.app

If you are told that the application is from an unidentified developer, right-click (or Ctrl-click) the deal.II.app and choose open. You’ll only need to do this once. If you only see “can’t be opened…”, go to System Settings -> Privacy & Security, scroll to Security, click Open Anyway next to deal.II.app, then Open.

(Terminal) alternative: xattr -dr com.apple.quarantine /Applications/deal.II.app and then open it normally.

(Optional) Add the one-liner printed by the app to your shell init (~/.zshrc or ~/.bashrc) to enable the environment in every Terminal.

System requirements
- Apple Silicon (M1/M2/M3/M4), arm64
- macOS 15 or newer (use Sequoia build on macOS 15; use Tahoe on macOS 26)
- Xcode Command Line Tools installed


Notes
- These are fully native builds; no Rosetta prompts.
- C++17 is enabled throughout.

Enjoy!
Luca.