macOS Big Sur (11) became generally available on GitHub-hosted runners in August 2021. Over the next 8 weeks, jobs using the macos-latest runner label will migrate from Catalina (10.15) to Big Sur (11). During migration, you can determine if your job has migrated by viewing the Virtual Environment information in the Set up job step of your logs.

Start using GitHub Actions to build and publish apps for the Apple ecosystem by updating your jobs to include runs-on: macos-latest

jobs:
  build:
    runs-on: macos-latest
     steps:
      - uses: actions/checkout@v2
      - name: Build
        run: swift build
      - name: Run tests
        run: swift test

The macOS 11 Big Sur runner image has different tools and tool versions than macOS 10.15 Catalina. See the full list of changed software.

If you spot any issues with your workflows when using Big Sur, please let us know by creating an issue in the virtual-environments repository.