Build.scala

object Build {
  lazy val root = Project(id = "cupenya-root",
                          base = file("."))
    .settings(basicSettings: _*)
    .aggregate(engineApi, engineCore, frontendApi, frontendCore, consoleTools)
    
  lazy val engineApi = Project(id = "engine-api",
                               base = file("engine-api"))
    .settings(basicSettings: _*)
    
  lazy val engineCore = Project(id = "engine-core",
                                base = file("engine-core"))
    .settings(basicSettings: _*)
    .settings(sprayRunSettings: _*)
    .settings(aspectJSettings: _*)
    .dependsOn(engineApi)
    
  lazy val frontendApi = Project(id = "frontend-api",
                                 base = file("frontend-api"))
    .settings(basicSettings: _*)
    .dependsOn(engineApi)
    
  lazy val frontendCore = Project(id = "frontend-core",
                                  base = file("frontend-core"))
    .settings(basicSettings: _*)
    .settings(sprayRunSettings: _*)
    .settings(aspectJSettings: _*)
    
  lazy val consoleTools = Project(id = "console-tools",
                                  base = file("console-tools"))
    .settings(basicSettings: _*)
    .settings(sprayRunSettings: _*)
}

BuildSettings.scala

object BuildSettings {
  lazy val basicSettings = Seq(
    organization          := "***",
    scalaVersion          := "2.11.7",
    resolvers             ++= Dependencies.resolutionRepos,
    credentials           += Credentials(Path.userHome / ".sbt" / ".credentials"),
    javaOptions           += "-XX:+HeapDumpOnOutOfMemoryError",
    javaOptions           += "-Xmx8G",
    javaOptions           += "-XX:MaxPermSize=512M",
    javaOptions           += "-XX:+CMSClassUnloadingEnabled",
    javaOptions           += "-XX:+UseConcMarkSweepGC",
    scalacOptions         := Seq(
      "-encoding", "utf8",
      "-feature",
      "-unchecked",
      "-deprecation",
      "-target:jvm-1.7",
      "-Xlog-reflective-calls",
//      "-Xlog-implicits",
      "-optimise",
      "-Yclosure-elim",
      "-Yinline",
      "-Ybackend:GenBCode"
    ),
    incOptions := incOptions.value.withNameHashing(false),
    // for WAR packing
    exportJars           := true,

    // generate junit report
    testOptions in Test += Tests.Argument(TestFrameworks.Specs2, "console", "junitxml")
  )
}