When a plugin or archetype is downloaded from an artifact repository the Griffon build will place a copy of it in the griffon-local repository. This speeds up searches and further plugin installations. If you would like to specify a different local repository to be used as a cache then define a value for the griffon.artifact.repository.default.install key.

Assuming that 'my-local-repo' is configured in the project's settings then the following command will download the miglayout plugin and place a copy in that specific repository.

griffon -Dgriffon.artifact.repository.default.install='my-local-repo' install-plugin miglayout