Play 2.1 with Scala 2.10 and Jasmine sbt package, with auto-recompilation of LESS (including bootstrap), Jenkins build info, with coffeescript recompilation on (for sources and for specs in coffeescript). Sugar to taste.

Build.scala

import sbt._
import sbt.Keys._
import play.Project._
import sbtbuildinfo.Plugin._
import com.gu.SbtJasminePlugin._

object ApplicationBuild extends Build {

  val appName         = "your-app-name"
  val appVersion      = "1.0-SNAPSHOT"

  /* Scala Code Coverage Tool; to run it from the Play console: 
   * scct:test
   *
   * and view the output (with Firefox, due to cross-site issues) at:
   * file://<project-location>/target/scala-2.10/coverage-report/index.html
   */
  lazy val scctSettings = Defaults.defaultSettings ++ Seq(ScctPlugin.instrumentSettings : _*)
  lazy val sysProps = scala.util.Properties

  // Check first for a -D flag, then an environment variable
  private def resolveKey(key:String) = {
    sysProps.propOrElse( key, sysProps.envOrElse(key, "N/A"))
  }

  val appDependencies = Seq(
    // Add your project dependencies here,
    jdbc,
    anorm,
    "org.scalaz" %% "scalaz-core" % "7.0.3",
    "org.mockito" % "mockito-all" % "1.9.5"
  )

  // Only compile the custom bootstrap.less file and any other *.less file in the stylesheets directory
  def customLessEntryPoints(base: File): PathFinder = ( (base / "app" / "assets" / "stylesheets" / "custom" / "custom.less") +++ (base / "app" / "assets" / "stylesheets" * "*.less") )

  val main = play.Project(appName, appVersion, appDependencies, settings = Defaults.defaultSettings ++ buildInfoSettings ++ scctSettings)
      .settings(
    testOptions in Test += Tests.Argument("junitxml", "console"),

    // include 3rd-party javascript libraries
    unmanagedResources in Compile ++= (file("public/javascripts") ** "*.js").get,

    sourceGenerators in Compile <+= buildInfo,
    buildInfoKeys := Seq[BuildInfoKey](name, version, scalaVersion, sbtVersion),
    // Get pertinent build info from Jenkins - these properties are set at build time:
    // https://wiki.jenkins-ci.org/display/JENKINS/Building+a+software+project#Buildingasoftwareproject-below
    buildInfoKeys ++= Seq[BuildInfoKey](
      "extraInfo"     -> resolveKey("EXTRA_INFO"),
      "jenkinsBuild"  -> resolveKey("BUILD_NUMBER"),
      "buildId"       -> resolveKey("BUILD_ID"),
      "builtBy"       -> resolveKey("NODE_NAME"),
      "gitBranch"     -> resolveKey("GIT_BRANCH"),
      "gitVersion"    -> resolveKey("GIT_COMMIT")),
    buildInfoPackage := "util"
  )
    .settings( lessEntryPoints <<= baseDirectory(customLessEntryPoints))
    .settings(jasmineSettings : _*)
    .settings(

      // jasmine configuration, overridden as we don't follow the default project structure sbt-jasmine expects
      appJsDir <+= baseDirectory / "target/scala-2.10/resource_managed/main/public/javascripts",
      appJsLibDir <+= baseDirectory / "public/javascripts",

      jasmineTestDir <+= baseDirectory / "test/javascripts/",   // specs should be in test/js/specs/exampleSpec.js
      jasmineConfFile <+= baseDirectory / "test/javascripts/test.dependencies.js",

      // link jasmine to the standard 'sbt test' action. Now when running 'test' jasmine tests will be run
      // and after that other Play tests will be executed.
      (test in Test) <<= (test in Test) dependsOn (jasmine),

      // ensures copy-resources are called (if need updating) before running jasmine task (for coffeescript)
      (jasmine) <<= (jasmine) dependsOn (copyResources in Compile),

      // auto watch javascript spec directories
      unmanagedResources in Test ++= (file("test/javascripts") ** "*.js").get,

      // adds coffeescript source files recompilation in ~jasmine
      unmanagedResources in Test ++= (file("app/assets/javascripts") ** "*.coffee").get
  )
}