ConcurrentUpdate takes a list of dependencies and updates in parallel.

LazyConcurrentUpdate updates only deps that are not already checkout out at the right version.

NewInstaller returns an Installer instance ready to use.

NewUpdateTracker creates a new instance of UpdateTracker ready for use.

SetReference is a command to set the VCS reference (commit id, tag, etc) for a project.

VcsGet figures out how to fetch a dependency, and then gets it.

VcsUpdate updates to a particular checkout based on the VCS setting.

VcsVersion set the VCS version for a checkout.

Installer provides facilities for installing the repos in a config file.

MissingPackageHandler is a dependency.MissingPackageHandler.

UpdateTracker holds a list of all the packages that have been updated from an external source.

VersionHandler handles setting the proper version in the VCS.