the project file: designator, dependencies, resolutions, build/test/run clauses. Written by the author (or generated by ‘ergo init’).
the lock file: the resolved dependency graph with exact commits. Generated by ‘ergo’; committed with the project; rewritten only by ‘ergo update’.
the user configuration.
the user layer of the collection database.
the site layer of the collection database.
the shared cache of cloned repositories, indexed by collection, path, and version.