conda-exec 0.3.0

Ephemeral package execution for conda -- run any conda package without installing it

conda-exec

Ephemeral package execution for conda. Run commands from conda packages without installing them permanently.

conda exec ruff check .
ce ruff check .

conda-exec creates a cached, isolated environment for the tool, runs it, and exits. The environment is reused on later runs but is not added to PATH permanently.

Installation

conda install -c conda-forge conda-exec

Install conda-pypi for scripts with PyPI dependencies, and conda-lockfiles for script lock support.

Usage

# Run a tool (creates cached environment on first use)
conda exec ruff check .
ce ruff check .               # standalone alias

# Pin a version
conda exec "ruff>=0.4,<0.5" check .

# Add extra packages
conda exec --with pytest ruff check .
conda exec --with "python=3.12" jupyter lab

# Use a specific channel
conda exec -c bioconda samtools view file.bam

# Run a script with inline dependencies (PEP 723)
conda exec script.py

# Record a repeatable script environment
conda exec --lock script.py

# Force re-creation of cached environment
conda exec --refresh ruff check .

How it works

1. Computes a cache key from the tool name, specs, and channels
2. Checks ~/.conda/exec/envs/ for a cached environment
3. On cache miss: solves and installs via conda's configured solver backend
4. Finds the binary in the environment's bin/ directory
5. Runs it directly via subprocess.run with PATH prepended
6. Forwards the tool's exit code

Documentation

Full documentation at conda-incubator.github.io/conda-exec.

Contributing

pixi install
pixi run check          # lint + format + typecheck
pixi run -e test test   # run tests

License

BSD-3-Clause