Some projects only use a portion of the workspace and, in such cases, it is not necessary to check out the entire workspace. For example, when accessing a large remote repository to build a sub-module.

If you specify a sub-path, the plugin makes a "best effort" to ensure that only the sub-path is populated. This means that the files within the sub-path will be fetched, at least, but side-effects may result in files from other paths being fetched as well.

Note that the changelog does not filter by sub-path. Thus, any change in the repository will trigger a build.

When using a workspace, you must update the workspace which populates any changed files and not just the files in the sub-path. The subsequent populate ensures that all the files in the sub-path are fetched, at least.