Reuse property with version number when adding a dependency in sbt

build, dependencies, sbt, scala

Solution

You need to tell the system that `libraryDependencies` now depends on `scalaVersion`:

libraryDependencies <+= (scalaVersion) { sv => "org.scala-lang" % "scala-swing" % sv }

(that's my preferred formatting; it's actually invoking the `apply` method on `scalaVersion` so you could write it a few different ways, e.g., `scalaVersion("org.scala-lang" % "scala-swing" % _)`.)

If you had multiple settings you wanted to depend on simultaneously, you'd apply on the tuple of them:

foo <<= (scalaVersion, organization) { (sv, o) => o + " uses Scala " + sv }

Problem

I have a project built with sbt 0.11. I'm trying to create a simple UI with Scala Swing, so first thing is to add a dependency on scala-swing in my build.sbt: ``` libraryDependencies += "org.scala-lang" % "scala-swing" % "2.9.1-1" ``` But I have a SettingKey scalaVersion defined: ``` scalaVersion := "2.9.1-1" ``` How can I reference that property? If I try to use it like ``` libraryDependencies += "org.scala-lang" % "scala-swing" % scalaVersion ``` Compiler complains that it found sbt.SettingKey[String] while String is expected. There are methods `get(...)` and `evaluate(...)` on SettingKey but they require some Setting[Scope] parameter to be passed in. What is the simplest way to just reference this property?

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