sbt/notes/2.0.0/remote-project-update.md

Updating remote VCS project dependencies

sbt now supports automatic updating of remote VCS project dependencies (Git, Mercurial, Subversion) via a configurable update strategy.

By default the strategy is Manual — remote projects are never updated automatically during update. To change this, set repositoryUpdateStrategy per dependency:

lazy val dep = RootProject(uri("git:file:///path/to/repo"))

lazy val root = project.dependsOn(dep).settings(
  // Pull latest on every `update`:
  dep / repositoryUpdateStrategy := RepositoryUpdateStrategy.Always,
  // Or pull at most once per hour:
  dep / repositoryUpdateStrategy := RepositoryUpdateStrategy.Every(1.hour),
)

When changes are detected, sbt will warn that a reload is needed to pick up the new sources.

The updateRemoteProjects command force-updates all remote VCS dependencies regardless of strategy and automatically reloads the build.