GitTwin

Run multiple git commits, branches, or tags of the same application side by side, each in its own isolated environment — for comparison, debugging, regression testing, and demonstrations.

Status: early / pre-alpha. The pipeline described below is the design target; the CLI is just getting started.

Why

Reproducing "it worked on commit X but not on commit Y" usually means stashing changes, checking out refs one at a time, and juggling ports, dependencies, and env files by hand. GitTwin is meant to make that a single command:

1. Point it at a repo and a list of refs (commits, branches, or tags).
2. It spins up an isolated environment — its own worktree, dependencies, and ports — for each ref.
3. You run, compare, and debug them side by side, without one checkout clobbering another.
4. Tear it all down in one command when you're done.

Install

uv add gittwin
pip install gittwin

Usage

gittwin about
gittwin --version

Development

This project uses uv for dependency management.

uv sync --extra dev   # install package + dev deps into .venv
uv run pytest -q      # run tests
uv run gittwin about  # run the CLI