Installation

Install LARDON and its dependencies using Pixi on Linux (x86-64) or macOS (x86-64).

LARDON uses Pixi to manage all of its dependencies. You do not need a pre-existing Python or conda environment — Pixi handles the full dependency graph, including xrootd, numba, h5py, and other packages.

Supported platforms: linux-64, osx-64

If you previously added xrootd to a conda environment, remove it before proceeding:

conda remove xrootd

The conda-installed xrootd conflicts with server settings used by grid tools such as git and HTCondor.

1. Install Pixi

   Run the Pixi installer script:

   curl -fsSL https://pixi.sh/install.sh | sh
   

   After installation, restart your shell or follow the instructions printed by the installer to update your PATH.

2. Clone the repository and install dependencies

   Clone the LARDON repository and install all environments:

   git clone https://github.com/dune-lardon/lardon.git
   cd lardon
   pixi install -a
   

   The -a flag installs all defined environments at once. This may take a few minutes on the first run.

3. Understand the available environments

   The pixi.toml file defines three environments:

   Environment	Contents	Recommended use
   prod	Minimal — only the libraries required to run LARDON	Submitting batch jobs
   test	prod + debugging and test tools	Development and validation
   default	test + analysis libraries (IPython, uproot, bokeh, iminuit, etc.)	Interactive analysis

   The default environment is used when no environment is explicitly specified.

4. Activate LARDON

   There are two ways to run LARDON after installation:

   Option A — run directly via Pixi (no activation needed):

   pixi run lardon <options>
   

   Option B — activate the environment in your current shell, then run as a normal command:

   eval "$(pixi shell-hook)"
   lardon <options>
   

   To use a specific environment (for example prod), pass the -e flag:

   pixi run -e prod lardon <options>
   eval "$(pixi shell-hook -e prod)"
   
5. Configure environment variables

   LARDON requires three environment variables to locate source data and store outputs. Review and edit set_lardon.sh in the repository root, then source it:

   source set_lardon.sh
   

   The script sets:

   Variable	Purpose
   LARDON_PATH	Path to the LARDON source code (src/lardon)
   LARDON_RECO	Directory where reconstructed HDF5 output files are written
   LARDON_PLOT	Directory where control plots are saved

   By default, LARDON_RECO is set to $PWD/reco and LARDON_PLOT to $PWD/plots. Adjust these paths for your setup before running.

   To open files stored outside of CERN or Fermilab via XRootD, uncomment the two xroot lines in set_lardon.sh and ensure your JIRA/rucio authentication is configured.

Notes on conda

A conda environment YAML file is included in the repository for reference, but it is unsupported. Pixi is the recommended and supported way to install LARDON.