When running:

    - name: Set up JDK 1.11
      uses: actions/setup-java@v1
      with:
        java-version: 1.11

On a self-hosted runner, the build fails saying:

1457fa28-9216-4663-b693-074afad52b42.sh: line 1: mvn: command not found

It works fine on github-hosted runners.