Compiler Plugin Support 

There is some special support for using compiler plugins. You can set autoCompilerPlugins to true to enable this functionality.

autoCompilerPlugins := true

To use a compiler plugin, you either put it in your unmanaged library directory (lib/ by default) or add it as managed dependency in the plugin configuration. addCompilerPlugin is a convenience method for specifying plugin as the configuration for a dependency:

addCompilerPlugin("org.scala-tools.sxr" %% "sxr" % "0.3.0")

The compile and testCompile actions will use any compiler plugins found in the lib directory or in the plugin configuration. You are responsible for configuring the plugins as necessary. For example, Scala X-Ray requires the extra option:

// declare the main Scala source directory as the base directory
scalacOptions :=
    scalacOptions.value :+ ("-Psxr:base-directory:" + (Compile / scalaSource).value.getAbsolutePath)

You can still specify compiler plugins manually. For example:

scalacOptions += "-Xplugin:<path-to-sxr>/sxr-0.3.0.jar"

Continuations Plugin Example 

Support for continuations in Scala 2.12 is implemented as a compiler plugin. You can use the compiler plugin support for this, as shown here.

val continuationsVersion = "1.0.3"

autoCompilerPlugins := true

addCompilerPlugin("org.scala-lang.plugins" % "scala-continuations-plugin_2.12.2" % continuationsVersion)

libraryDependencies += "org.scala-lang.plugins" %% "scala-continuations-library" % continuationsVersion

scalacOptions += "-P:continuations:enable"

Version-specific Compiler Plugin Example 

Adding a version-specific compiler plugin can be done as follows:

val continuationsVersion = "1.0.3"

autoCompilerPlugins := true

libraryDependencies +=
    compilerPlugin("org.scala-lang.plugins" % ("scala-continuations-plugin_" + scalaVersion.value) % continuationsVersion)

libraryDependencies += "org.scala-lang.plugins" %% "scala-continuations-library" % continuationsVersion

scalacOptions += "-P:continuations:enable"