In sbt, how do you add a plugin that's in the local filesystem?

Question

If I want to add a plugin that\'s in a local directory outside the project tree, what\'s the right way to do that? Say I clone something simple like https://github.com/step

Answer 1

Something like this in project/project/Build.scala should do it:

import sbt._
object PluginDef extends Build {
    lazy val projects = Seq(root)
    lazy val root = Project("plugins", file(".")) dependsOn( shPlugin )
    lazy val shPlugin = uri("file:///tmp/sbt-sh")
}

Note that that the doubly-nested project directories are required. I'm not aware of any way to do this from an .sbt file (there may be a way, but I don't know what it is).

This is documented here (see "1d) Project dependency").