Installation¶

Using pixi (recommended)¶

Pixi manages all of FairShip's dependencies via the pixi.toml and activate.sh shipped in the FairShip clone. The activation script sets FAIRSHIP, GEOMPATH, and similar paths to the clone, so the pixi project root must be the FairShip clone itself.

1. Install pixi.
2. Clone and build:

   git clone https://github.com/ShipSoft/FairShip.git
   cd FairShip
   pixi run build
   

3. Run commands inside the environment:

   pixi run python macro/run_simScript.py --tag my-simulation
   

   Or start a shell:

   pixi shell
   python macro/run_simScript.py --tag my-simulation
   

Pre-built FairShip packages are also published to the prefix.dev/ship channel; see the FairShip README for that flow.

Legacy releases (CVMFS + aliBuild, ≤26.04)¶

These instructions are kept for users on existing CVMFS releases up to 26.04 and for legacy branches (SHiP-2018, muflux). New development uses pixi — see Using pixi above and the shipdist page.

With CVMFS (e.g. lxplus):

source /cvmfs/ship.cern.ch/$SHIP_RELEASE/setUp.sh
aliBuild build FairShip --always-prefer-system --config-dir $SHIPDIST --defaults release
alienv enter FairShip/latest

Without CVMFS, install aliBuild via pipx/pip, clone shipdist alongside FairShip, and run aliBuild build FairShip with the same defaults.