Build workspace and parallel builds
Each build has its own workspace: a directory that is sync'd between the Continua server and any agents the build runs on. It contains things like a serialized copy of the build's variables, any artifacts that are registered, and the build log. When a build is run on an agent, the correct version of the source is copied from the cache into the workspace. Using a copy means that we can run multiple builds of the same stage, at the same time, on the same agent without any conflicts. This is very useful if you set up feature branch builds.
Although a copy of the source is placed in the workspace on the agent, we don't sync this back to the server. The performance cost of moving a potentially large amount of data around for every build is too high. If you need changes to be available to later stages, you can specify which files are moved to and from agents for each stage.