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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:
EnvironmentContentsRecommended use
prodMinimal — only the libraries required to run LARDONSubmitting batch jobs
testprod + debugging and test toolsDevelopment and validation
defaulttest + 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:
VariablePurpose
LARDON_PATHPath to the LARDON source code (src/lardon)
LARDON_RECODirectory where reconstructed HDF5 output files are written
LARDON_PLOTDirectory 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.

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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.

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