Installation changes — what existing users need to know

The dependency overhaul (August 2026) changed how C-Star Forge is installed and managed. If you had a working setup before, here’s what’s different.

Action needed¶

The conda environment is renamed: cstar-forge-v0 → cstar-forge-env. Rebuild with ./dev-setup.sh --clean (your old env keeps working, but docs, scripts, and the Jupyter kernel now use the new name — select the cstar-forge-env kernel in notebooks).
Python 3.12+ is now required (was 3.11). A --clean rebuild handles this.

pyproject.toml is now the single source of truth for dependencies. environment.yml is a generated file — don’t edit it by hand; edit pyproject.toml and regenerate (CI enforces this).
dev-setup.sh is much smaller but behaves the same (same flags, plus --with-compilers). The HPC hardening it used to inline now lives in scripts/harden-env.sh; kernel registration lives in the package itself (cstar forge register-kernel, cstar_forge/register_kernel.py).
Dependencies now come from real releases: roms-tools ≥ 4.1.0 (conda-forge; dask is a core dependency now — the [dask] extra is gone) and cstar-ocean ≥ 0.8 (PyPI and conda-forge).

pixi for development: pixi install -e dev reproduces the exact locked environment from pixi.lock — a single-binary install that also works on HPC without admin rights.
Plain-conda lockfile replay: each release publishes explicit-spec + pinned-requirements artifacts for machines that only have conda. See docs/installation.md (“Reproducible installs”).

pip install cstar-forge and conda install -c conda-forge cstar-forge (first release + feedstock are in progress).