title: How to overcome "there were 1 feature warning(s); re-run with -features for details"
body: <p>I am new to Scala, Scala-IDE, and Play 2.1 and am working my way through the tutorials.  Today I noted that the Eclipse Project emitted by the "todolist" tutorial shows up in the Scala-IDE with a Warning that I don't understand and would like to see go away.</p>
  
  <p>This answer <a href="https://stackoverflow.com/questions/15533706/how-to-get-more-information-about-feature-flag-warning">How to get more information about &#39;feature&#39; flag warning?</a> suggests that I need only add...</p>
  
  <pre><code>scalacOptions ++= Seq(... "-feature")
  </code></pre>
  
  <p>...to my sbt build definition file which, I thought, was project/Build.scala for a Play 2.1 project.  Trying to put it in there, however...</p>
  
  <pre><code>import sbt._
  import Keys._
  import play.Project._
  
  object ApplicationBuild extends Build {
  
    val appName         = "todolist"
    val appVersion      = "1.0-SNAPSHOT"
  
    val appDependencies = Seq(
      // Add your project dependencies here,
      jdbc,
      anorm
    )
  
    val main = play.Project(appName, appVersion, appDependencies).settings(
      // Add your own project settings here
      scalacOptions ++= Seq(... "-feature")
    )
  
  }
  </code></pre>
  
  <p>..., results in a compile error...</p>
  
  <pre><code>[info] Loading project definition from /Users/bobk/work/todolist/project
  [error] /Users/bobk/work/todolist/project/Build.scala:18: illegal start of simple expression
  [error]     scalacOptions ++= Seq(... "-feature")
  [error]                           ^
  [error] /Users/bobk/work/todolist/project/Build.scala:21: ')' expected but '}' found.
  [error] }
  [error] ^
  [error] two errors found
  [error] (compile:compile) Compilation failed
  Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? 
  </code></pre>
  
  <p>If I want to set scalacOptions in my sbt build definition in Play 2.1 where do I specify it and how?</p>