tox-gh-actions

tox-gh-actions is a tox plugin which helps running tox on GitHub Actions with multiple different Python versions on multiple workers in parallel. This project is inspired by tox-travis.

• Features
• Usage
• Examples
  • Basic Example
    • tox-gh-actions Configuration
    • Workflow Configuration
  • Advanced Examples
    • Factor-Conditional Settings: Python Version
    • Factor-Conditional Settings: Environment Variable
    • tox requires
  • Overriding Environments to Run
• Versioning
• Versions and Compatibility
• Understanding Behavior of tox-gh-actions
  • How tox-gh-actions Works
  • Logging

Features

When running tox on GitHub Actions, tox-gh-actions

• detects which environment to run based on configurations and
• provides utilities such as grouping log lines.

Usage

1. Add configurations under [gh-actions] section along with tox's configuration.

   • It will be pyproject.toml, tox.ini, or setup.cfg. See tox's documentation for more details.

2. Install tox-gh-actions package in the GitHub Actions workflow before running tox command.

Examples

Basic Example

The following configuration will create 3 jobs when running the workflow on GitHub Actions.

• On Python 3.10 job, tox runs py310 environment
• On Python 3.12 job, tox runs py312 environment
• On Python 3.14 job, tox runs py314 and mypy environments

tox-gh-actions Configuration

Add [gh-actions] section to the same file as tox's configuration.

If you're using tox.ini:

[tox]
envlist = py310, py312, py314, mypy

[gh-actions]
python =
    3.10: py310
    3.12: py312
    3.14: py314, mypy

[testenv]
...

If you're using setup.cfg:

[tox:tox]
envlist = py310, py312, py314, mypy

[gh-actions]
python =
    3.10: py310
    3.12: py312
    3.14: py314, mypy

[testenv]
...

If you're using pyproject.toml:

[tool.tox]
legacy_tox_ini = """
[tox]
envlist = py310, py312, py314, mypy

[gh-actions]
python =
    3.10: py310
    3.12: py312
    3.14: py314, mypy

[testenv]
"""

Workflow Configuration

.github/workflows/<workflow>.yml:

name: Python package

on:
  - push
  - pull_request

jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ['3.10', '3.12', '3.14']

    steps:
    - uses: actions/checkout@v5
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v6
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip
        python -m pip install tox tox-gh-actions
    - name: Test with tox
      run: tox

Advanced Examples

Factor-Conditional Settings: Python Version

The following configuration will create 2 jobs when running the workflow on GitHub Actions.

• On Python 3.12 job, tox runs py12-django42 environment
• On Python 3.13 job, tox runs py313-django42 and py313-django52 environments

tox.ini:

[tox]
envlist = py312-django42, py313-django{42,52}

[gh-actions]
python =
    3.12: py312
    3.13: py313

[testenv]
...

When using pre-release versions of Python, please do not specify -beta or -dev in tox.ini.

.github/workflows/<workflow>.yml:

...
jobs:
  build:
    strategy:
      matrix:
        python-version: [3.14, 3.15.0-beta.3]
...

tox.ini:

[tox]
envlist = py39, py310

[gh-actions]
python =
    3.14: py314
    3.15: py315
    # The following won't work
    # 3.15-beta.3: py315
    # 3.15-dev: py315

[testenv]
...

Added in 3.5.0: To use a free-threaded Python build, add the t suffix.

tox.ini:

[tox]
envlist = py314, py314t

[gh-actions]
python =
    3.14: py314
    3.14t: py314t

[testenv]
...

PyPy is also supported in the python configuration key. Support of Pyston is experimental and not tested by our CI.

tox.ini:

[tox]
envlist = py313, py314, pypy3, pyston38

[gh-actions]
python =
    3.13: py313
    3.14: py314, mypy
    pypy-3.11: pypy3
    pyston-3.8: pyston38

[testenv]
...

[testenv:pyston38]
basepython = pyston38

You can also specify without minor versions in the python configuration key.

tox.ini:

[tox]
envlist = py3, pypy3

[gh-actions]
python =
    3: py3, mypy
    pypy-3: pypy3

[testenv]
...

If there are multiple matching Python versions in the configuration, only the most precise one is used. For example, if you are running CPython 3.14 and gh-actions.python has both 3 and 3.14, tox-gh-actions gets factors only from the key 3.14.

Changed in 3.0: pypy3 is not supported in the configuration anymore. Please use pypy-3 instead.

Factor-Conditional Settings: Environment Variable

You can also use environment variable to decide which environment to run. The following is an example to install different dependency based on platform. It will create 9 jobs when running the workflow on GitHub Actions.

• On Python 3.10/ubuntu-latest job, tox runs py310-linux environment
• On Python 3.12/ubuntu-latest job, tox runs py312-linux environment
• and so on.

.github/workflows/<workflow>.yml:

name: Python package

on:
  - push
  - pull_request

jobs:
  build:
    runs-on: ${{ matrix.platform }}
    strategy:
      matrix:
        platform: [ubuntu-latest, macos-latest, windows-latest]
        python-version: ['3.10', '3.12', '3.14']

    steps:
    - uses: actions/checkout@v5
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v6
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip
        python -m pip install tox tox-gh-actions
    - name: Test with tox
      run: tox
      env:
        PLATFORM: ${{ matrix.platform }}

tox.ini:

[tox]
envlist = py{310,312,314}-{linux,macos,windows}

[gh-actions]
python =
    3.10: py310
    3.12: py312
    3.14: py3114

[gh-actions:env]
PLATFORM =
    ubuntu-latest: linux
    macos-latest: macos
    windows-latest: windows

[testenv]
deps =
  <common dependency>
  linux: <Linux specific deps>
  macos: <macOS specific deps>
  windows: <Windows specific deps>
...

Changed in 3.0: Environment variables should not use lowercase letters. Because of the limitation in tox's configuration loading API, tox-gh-actions always convert keys in [gh-actions:env] to uppercase.

tox requires

If your project uses tox's requires configuration, you must add tox-gh-actions to the requires configuration as well. Otherwise, tox-gh-actions won't be loaded as a tox plugin.

[tox]
requires =
  tox-conda
  tox-gh-actions

Overriding Environments to Run

Changed in 2.0: When a list of environments to run is specified explicitly via -e option or TOXENV environment variable (tox's help), tox-gh-actions respects the given environments and simply runs the given environments without enforcing its configuration.

Before 2.0, tox-gh-actions was always enforcing its configuration even when a list of environments is given explicitly.

Versioning

This project follows PEP 440 and uses a format of major.minor.patch (X.Y.Z). The major version (X) will be incremented when we make backward incompatible changes to a public API. The public API of this project is the configuration of tox-gh-actions. The major version can be also incremented when we require a new version of tox.

This project tries not to introduce backward incompatibles changes as much as possible so that users don't need to update their project's configuration too frequently.

tox-gh-actions 3.x may drop support of unsupported Python 3.y versions in the future without bumping its major version.

Versions and Compatibility

We recommend to use the latest version of tox 4.x and tox-gh-actions 3.x. To use tox-gh-actions with tox 3.x, please install tox-gh-actions 2.x. The following table shows compatibility between tox and tox-gh-actions.

Understanding Behavior of tox-gh-actions

How tox-gh-actions Works

See ARCHITECTURE.md for more details.

Logging

tox-gh-actions writes log messages using the standard logging module. This is handy for understanding behavior of tox-gh-actions and for debugging tox-gh-actions. To see the log messages, please run tox -vv.