ReproMin

Turn a large failing repository into a small, verified bug reproduction.

ReproMin is a repository-scale test-case reducer for repeatable Maven, Gradle, and Python failures. It removes files, manifest entries, source structure, and selected text only while the same failure still occurs.

Maintainer-run Gradle pilot: 854 -> 11 files, with the same failure reproduced in 5/5 fresh copies.

Try a real reduction

With uv, run the published release without installing anything into your project or system Python:

uvx --from https://github.com/fly1d/repomin/releases/download/v0.1.0.dev11/repomin-0.1.0.dev11-py3-none-any.whl \
  repomin demo ./repomin-demo

The trusted, network-free demo normally finishes in a few seconds. Its key output looks like this:

ReproMin demo completed.
Reduced: 3 files / 855 bytes -> 2 files / 276 bytes in 14 attempts.
Removed: unused.txt and two unrelated input lines.
Validated: exact payload fingerprint.
Next: run `repomin doctor --help` before trying your own repository.

The demo leaves the reduced payload and evidence report available for inspection and prints a copyable validation command. Continue with the five-minute quick start, the PowerShell guide, or the Chinese guide. For a failing CI job, start with the GitHub Action.

Project status: ReproMin is a pre-alpha feasibility build. Use it on a reproducible failure in a repository you trust. The default host backend runs your command directly and is not a sandbox.

Evidence so far

Two maintainer-run pilots demonstrate the current technical scope:

Pilot	Before	After	Fresh-copy evidence
Gradle #38843	854 files, 3.8 MB	11 files, 87.9 KB	5/5 replays + cold start
tsdown #979	14 files	8 files	3/3 replays

These are feasibility results, not independent adoption or a promise that every repository will shrink by the same amount. The current milestone is five non-maintainer workflows.

When to use it

Use ReproMin when a bug already repeats but the repository is too large to share, review, or keep as a regression fixture. It produces a smaller payload, a human-readable receipt, and a machine-readable report that can be validated or replayed.

Your goal	Start with
Find the commit that introduced a regression	git bisect
Capture the runtime environment and dependencies	A container or ReproZip
Minimize source or compiler inputs	C-Reduce, C-Vise, Perses, or Shrink Ray
Shrink a build or application repository and retain evidence	ReproMin

ReproMin treats your build, test, or reproduction command as the authority. It does not diagnose the root cause or prove that the remaining code is correct.

Use it on a real failure

A first run has three steps. ReproMin requires Python 3.9+ and has no runtime dependencies. From a virtual environment, install the current pre-alpha release, then check readiness, run a bounded reduction, and validate the exported evidence:

python -m pip install \
  "https://github.com/fly1d/repomin/releases/download/v0.1.0.dev11/repomin-0.1.0.dev11-py3-none-any.whl"

repomin doctor . \
  --command 'python -m pytest -q tests/test_checkout.py' \
  --match 'FAILED tests/test_checkout.py' \
  --output ../checkout-repro

repomin . \
  --command 'python -m pytest -q tests/test_checkout.py' \
  --match 'FAILED tests/test_checkout.py' \
  --max-attempts 25 \
  --max-duration 300 \
  --output ../checkout-repro

repomin report validate ../checkout-repro.repomin/report.json \
  --payload ../checkout-repro \
  --format markdown

ReproMin works in temporary copies and never changes the source repository. Use a signal that identifies the target failure: stable output (--match), an exact exit code, an exception identity, or a process-failure signature. The quick start explains the complete workflow; use the Doctor guide for failed checks and the replay guide before executing an exported command.

Local CLI or GitHub Action

The CLI is best for interactive reduction. The reusable GitHub Action can reduce a repeatable CI failure and upload the payload and validated report as an artifact:

- uses: fly1d/repomin@v0.1.0.dev11
  with:
    command: python -m pytest -q tests/test_checkout.py
    match: FAILED tests/test_checkout.py
    max-attempts: 25
    max-duration: 300

Pin a reviewed release tag or full commit SHA in real workflows.

Current coverage

Layer	Coverage
Repository tree	Files and directories in any trusted local repository
Build manifests	Maven, Gradle, Python, Pipenv, Node, Composer, MSBuild, Bundler, Cargo, and Go
Source structure	Native Java and Python reducers
Selected text	Explicit UTF-8 files reduced by line
Custom semantic edits	Optional OpenAI-compatible HTTP integration; every edit still passes the oracle

Other languages still benefit from repository, manifest, and explicit text reduction. Start with the nearest ecosystem example.

Safety and privacy

The host backend runs the supplied command with your user account. It is not a sandbox. Only run repositories and commands you trust. Docker can reduce access when configured carefully, but it is not a complete security boundary. Read SECURITY.md before handling third-party code.

Do not publish credentials, private URLs, proprietary source, customer data, raw logs, commands, or environment values. The Markdown validation summary is path-free and allow-listed, but it does not make the payload or full report safe to publish.

Documentation and community

• Start: quick start, Windows, Chinese, and ecosystem examples.
• Try a real failure: offer a sanitized public case in pilot issue #11.
• Ask or share: use Q&A or Show and tell.
• Contribute: read CONTRIBUTING.md and choose an open starter task.

The documentation index covers configuration, reports, and design. Use SUPPORT.md for other help and SECURITY.md for private vulnerability reports.

Apache-2.0 licensed. See LICENSE.