Pixi can now be used in github actions

In CI/CD workflows, dependency management is often a key factor determining build efficiency and reliability. Recently, I tried the setup-pixi GitHub Action in a static website deployment pipeline.

Why Choose Pixi?

When I first chose Pixi, it was mainly because it builds on conda‘s pre‑compiled resources, offers faster dependency resolution than mamba, and has a lock‑file mechanism similar to nodejs. These features make it ideal for rapid environment migration and deployment, which are essential in bioinformatics where software changes frequently.

After using it for over a year, I not only manage bioinformatics environments with Pixi but also use it to set up and maintain development environments. Currently, except for system‑resident services like MySQL that it cannot handle, Pixi can install every toolchain I need for my work.

Using a single tool to manage various toolchains, along with its built‑in simple workflow configuration, provides an excellent user experience.

The only minor drawback was a slight inconvenience when I had to use GitHub Actions for automation at my supervisor’s request. Since pixi still involves virtual environments, installing and running it required some extra environment‑variable tweaks.

However, the official team had already developed the setup-pixi action long ago—I just didn’t know about it…

Using setup-pixi in GitHub Actions

Using setup-pixi is straightforward. Here’s an example:

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name: DEPLOY

on:
  push:
    branches:
      - main
  workflow_dispatch:

jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        environment: [website]

    steps:
      - name: Checkout repository
        uses: actions/checkout@v3
        with:
          ref: main

      - name: Setup Pixi
        uses: prefix-dev/setup-pixi@v0.9.3
        with:
          pixi-version: v0.59.0
          environments: ${{ matrix.environment }}

      - name: Run Pixi Task
        run: |
          pixi run build

Step‑by‑Step Explanation

1. Checkout repository: Use actions/checkout to fetch the latest code. This must come before Setup Pixi because the pixi.toml and pixi.lock files reside in the project.
2. Setup Pixi: The prefix-dev/setup-pixi Action downloads and installs the specified version of Pixi, then automatically activates the environment defined in pixi.toml that matches the one specified in the matrix (in this example, the website environment).
3. Run Pixi Task: With the environment ready, you can freely invoke any task already defined in the project.

The whole process is clean and clear. The Pixi environment ensures dependency consistency during the build phase—define it once, and no further manual setup is needed.

Summary

By leveraging setup-pixi in GitHub Actions, we can easily harness Pixi’s powerful dependency‑management capabilities, simplify configuration, reduce manual setup time, and guarantee high consistency from development to production environments.