Runners are in charge of preparing an environment and executing an
Action in it.
Different implementations are free to choose their own way of creating that environment, and may choose to provide features such as sandboxing.
Since different types of runners will have similar functionality, buildbox-common provides a
Runner base class that can be used to reduce code duplication.
This is the simplest runner, providing no sandboxing. It invokes the build tools that are available on the local system.
It allows to execute commands in a sandbox created by userchroot.
It uses bubblewrap to provide sandboxing.