Development Setup

This page describes the supported local setup for working on AMMM3. The project is maintained with local verification scripts rather than a CI-first workflow, so your development environment needs to be able to run linting, pytest, and the packaging smoke checks directly.

Prerequisites

Python 3.12
A local environment manager such as Conda
A writable temporary directory such as /tmp for PyTensor caches and package verification artefacts

Create the Development Environment

The simplest supported path is the repository environment file:

conda env create -f environment.yml
conda activate ammm3-dev
python3 -m pip install -e .

If you know you will be running linting and tests frequently, install the optional extras as well:

python3 -m pip install .[lint,test]

Local Runtime Defaults

Some parts of the stack need writable cache directories. In restricted or sandboxed environments, set the same defaults used by the repo’s local verification scripts:

export PYTENSOR_FLAGS="base_compiledir=/tmp/pytensor,linker=py"
export JAX_PLATFORMS=cpu
export XDG_CACHE_HOME=/tmp

The Makefile already applies these defaults for make test and make smoke_mmm.

Common Commands

Lint and format

make check_lint
make lint
make check_format
make format

These targets cover src/, tests/, scripts/ and runme.py.

Tests

make test
pytest tests/<path>/test_*.py -v

Use targeted pytest first when you are working on a narrow area. Run the wider verification commands before closing substantial changes.

Local verification

make smoke_mmm
make verify_local
make verify_package
make verify_local_all

What these commands do:

make smoke_mmm runs the full configured timeseries pipeline. Its main fit uses four chains with 2,000 tuning and 3,000 retained draws each. The holdout fit uses four chains with 2,000 tuning and 2,000 retained draws each. This target is a substantial sampling run. Use the runner quickstart to reduce the fit workload, and separately reduce or disable holdout validation.
make verify_local runs formatting, linting, typing, and the configured test suite in sequence.
make verify_package builds package artefacts and validates an installed package smoke path.
make verify_local_all runs the local verification matrix and includes the packaging smoke step.

The package verifier builds the source distribution and wheel in a temporary directory, checks required package files, installs the wheel without resolving dependencies into an isolated virtual environment that can use the current Python environment’s dependencies, and imports the installed package from outside the checkout. It verifies packaging and import behaviour. It is not a fresh dependency-resolution test.

Important Working Files

File	Why it matters
`Makefile`	Primary local entry point for lint, test, smoke, and package verification
`environment.yml`	Supported dev environment definition
`pyproject.toml`	Packaging metadata, extras, Ruff, MyPy, and pytest configuration
`scripts/run_package_verification.py`	Package build and installed-wheel smoke verification
`ARCHITECTURE.md`	Contributor-facing module map and dependency rules

Local-Only Areas

The repo contains some directories that are useful locally but are not part of the shipped library surface:

.archive/ for archived planning and reference material
AGENTS.md for repository development and statistical boundaries
sandbox/ for ignored local scratch work

Keep temporary scripts in sandbox/ rather than mixing them into the package.

Troubleshooting

PyTensor cache permission errors

If you see errors related to .pytensor lock files or compiledir creation, export the runtime defaults shown above and rerun the command.

Package verification fails because `build` is missing

Run:

python3 -m pip install build

The make verify_package target does this automatically.

You are not sure which command to run

As a rule:

run targeted pytest and ruff while iterating
run make verify_local before finishing non-trivial code changes
run make verify_package when packaging, imports, or bundled assets changed