Question

It’s easy to declare managed library dependencies in SBT, eg

 libraryDependencies ++= Seq(
 "org.specs2" %% "specs2" % "1.12.2" % "test" ,
 "junit" % "junit" % "4.7" % "test"
)

And while it’s not as easy to declare project dependencies in SBT, I can do that too:

object RichMath extends Build {
  lazy val myApp = Project("RichMath", file(".")) dependsOn(richUtil)   
  lazy val richUtil = RootProject(file("../RichUtil"))
}

But in practice, I typically want to change between project mode, where changes are immediately visible in upstream projects, and library mode, where I must publish changes to see them in dependent projects, as code matures.

Early in code-base’s life, or whenever I’m wanting to make frequent changes across modules, I don’t want the hassle of re-publishing just to see changes upstream. But in stable/mature code, I want to specify exactly what version’s I’m depending upon.

It seems like SBT treats the two dependencies as completely different. Is there a more straight-forward way to switch between project- and library- dependencies than rewriting my build definition?

Answer 1

I have a few scenarios for my sbt scripts (tests, publishing, production). I start sbt from script (from bash, you may have other environment) with DO=TESTS sbt for example. This is my dynamic dependencies with regard of environment variable:

if (sys.env.contains("LOCAL_BUILD")) {
  Seq[Project.Setting[_]](
    unmanagedResourceDirectories in Compile <+= baseDirectory { _ / "src" / "main" / "scala" },
    libraryDependencies ++= {
      Seq(
        "org.digimead" %% "digi-lib-slf4j" % "0.2.1-SNAPSHOT" % "test",
        "org.digimead" %% "digi-lib-test" % "0.2.1-SNAPSHOT" % "test",
        "org.scalatest" %% "scalatest" % "1.9" % "test"
      )
    }
  )
} else {
  Seq[Project.Setting[_]](
   libraryDependencies ++= {
      Seq(
        "org.slf4j" % "slf4j-log4j12" % "1.7.1"
      )
    }
  )
}

As you can see I may have different project settings with single .sbt definition controlled by one environment variable. The environment variable affect all project/subproject bunch.