GitHub Action to set up the pixi package manager.

- uses: prefix-dev/[email protected]
  with:
    pixi-version: v0.20.0
    cache: true
    auth-host: prefix.dev
    auth-token: ${{ secrets.PREFIX_DEV_TOKEN }}
- run: pixi run test

version: 2
updates:
  - package-ecosystem: github-actions
    directory: /
    schedule:
      interval: monthly # or daily, weekly
    groups:
      dependencies:
        patterns:
          - "*"

To see all available input arguments, see the action.yml file.

The action supports caching of the pixi environment. By default, caching is enabled if a pixi.lock file is present. It will then use the pixi.lock file to generate a hash of the environment and cache it. If the cache is hit, the action will skip the installation and use the cached environment. You can specify the behavior by setting the cache input argument.

If you need to customize your cache-key, you can use the cache-key input argument. This will be the prefix of the cache key. The full cache key will be <cache-key><conda-arch>-<hash>.

In order to not exceed the 10 GB cache size limit as fast, you might want to restrict when the cache is saved. This can be done by setting the cache-write argument.

- uses: prefix-dev/[email protected]
  with:
    cache: true
    cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}

With pixi, you can create multiple environments for different requirements. You can also specify which environment(s) you want to install by setting the environments input argument. This will install all environments that are specified and cache them.

[project]
name = "my-package"
channels = ["conda-forge"]
platforms = ["linux-64"]

[dependencies]
python = ">=3.11"
pip = "*"
polars = ">=0.14.24,<0.21"

[feature.py311.dependencies]
python = "3.11.*"
[feature.py312.dependencies]
python = "3.12.*"

[environments]
py311 = ["py311"]
py312 = ["py312"]

The following example will install the py311 and py312 environments in different jobs.

test:
  runs-on: ubuntu-latest
  strategy:
    matrix:
      environment: [py311, py312]
  steps:
  - uses: actions/checkout@v4
  - uses: prefix-dev/[email protected]
    with:
      environments: ${{ matrix.environment }}

The following example will install both the py311 and the py312 environment on the runner.

- uses: prefix-dev/[email protected]
  with:
    # separated by spaces
    environments: >-
      py311
      py312
- run: |
    pixi run -e py311 test
    pixi run -e py312 test

There are currently three ways to authenticate with pixi:

• using a token
• using a username and password
• using a conda-token

For more information, see the pixi documentation.

Specify the token using the auth-token input argument. This form of authentication (bearer token in the request headers) is mainly used at prefix.dev.

- uses: prefix-dev/[email protected]
  with:
    auth-host: prefix.dev
    auth-token: ${{ secrets.PREFIX_DEV_TOKEN }}

Specify the username and password using the auth-username and auth-password input arguments. This form of authentication (HTTP Basic Auth) is used in some enterprise environments with artifactory for example.

- uses: prefix-dev/[email protected]
  with:
    auth-host: custom-artifactory.com
    auth-username: ${{ secrets.PIXI_USERNAME }}
    auth-password: ${{ secrets.PIXI_PASSWORD }}

Specify the conda-token using the conda-token input argument. This form of authentication (token is encoded in URL: https://my-quetz-instance.com/t/<token>/get/custom-channel) is used at anaconda.org or with quetz instances.

- uses: prefix-dev/[email protected]
  with:
    auth-host: anaconda.org # or my-quetz-instance.com
    conda-token: ${{ secrets.CONDA_TOKEN }}

setup-pixi allows you to run command inside of the pixi environment by specifying a custom shell wrapper with shell: pixi run bash -e {0}. This can be useful if you want to run commands inside of the pixi environment, but don't want to use the pixi run command for each command.

- run: | # everything here will be run inside of the pixi environment
    python --version
    pip install --no-deps -e .
  shell: pixi run bash -e {0}

You can even run Python scripts like this:

- run: | # everything here will be run inside of the pixi environment
    import my_package
    print("Hello world!")
  shell: pixi run python {0}

If you want to use PowerShell, you need to specify -Command as well.

- run: | # everything here will be run inside of the pixi environment
    python --version | Select-String "3.11"
  shell: pixi run pwsh -Command {0} # pwsh works on all platforms

You can specify whether setup-pixi should run pixi install --frozen or pixi install --locked depending on the frozen or the locked input argument. See the official documentation for more information about the --frozen and --locked flags.

- uses: prefix-dev/[email protected]
  with:
    locked: true
    # or
    frozen: true

If you don't specify anything, the default behavior is to run pixi install --locked if a pixi.lock file is present and pixi install otherwise.

There are two types of debug logging that you can enable.

The first one is the debug logging of the action itself. This can be enabled by running the action with the RUNNER_DEBUG environment variable set to true.

- uses: prefix-dev/[email protected]
  env:
    RUNNER_DEBUG: true

Alternatively, you can enable debug logging for the action by re-running the action in debug mode:

For more information about debug logging in GitHub Actions, see the official documentation.

The second type is the debug logging of the pixi executable. This can be specified by setting the log-level input.

- uses: prefix-dev/[email protected]
  with:
    # one of `q`, `default`, `v`, `vv`, or `vvv`.
    log-level: vvv

If nothing is specified, log-level will default to default or vv depending on if debug logging is enabled for the action.

On self-hosted runners, it may happen that some files are persisted between jobs. This can lead to problems or secrets getting leaked between job runs. To avoid this, you can use the post-cleanup input to specify the post cleanup behavior of the action (i.e., what happens after all your commands have been executed).

If you set post-cleanup to true, the action will delete the following files:

• .pixi environment
• the pixi binary
• the rattler cache
• other rattler files in ~/.rattler

If nothing is specified, post-cleanup will default to true.

On self-hosted runners, you also might want to alter the default pixi install location to a temporary location. You can use pixi-bin-path: ${{ runner.temp }}/bin/pixi to do this.

- uses: prefix-dev/[email protected]
  with:
    post-cleanup: true
    # ${{ runner.temp }}\Scripts\pixi.exe on Windows
    pixi-bin-path: ${{ runner.temp }}/bin/pixi

You can also use a preinstalled local version of pixi on the runner by not setting any of the pixi-version, pixi-url or pixi-bin-path inputs. This action will then try to find a local version of pixi in the runner's PATH.

setup-pixi will automatically pick up the pyproject.toml if it contains a [tool.pixi.project] section and no pixi.toml. This can be overwritten by setting the manifest-path input argument.

- uses: prefix-dev/[email protected]
  with:
    manifest-path: pyproject.toml

If you want to see more examples, you can take a look at the GitHub Workflows of this repository.

1. Clone this repository.
2. Run pnpm install inside the repository (if you don't have pnpm installed, you can install it with pixi global install pnpm).
3. Run pnpm dev for live transpilation of the TypeScript source code.
4. To test the action, you can run act (inside docker) or use ✨ CI driven development ✨.