title: How to prevent java.lang.OutOfMemoryError: PermGen space?
body: <p>I am frequently getting an <code>OutOfMemoryError</code> from SBT.</p>
  
  <pre><code>&gt; test
  [error] java.util.concurrent.ExecutionException: java.lang.OutOfMemoryError: PermGen space
  [error] Use 'last' for the full log.
  &gt; last
  [debug] Running task... Cancelable: false, check cycles: false
  [debug]
  [debug] Initial source changes:
  [debug]     removed:Set()
  [debug]     added: Set()
  [debug]     modified: Set()
  [debug] Removed products: Set()
  [debug] Modified external sources: Set()
  [debug] Modified binary dependencies: Set()
  [debug] Initial directly invalidated sources: Set()
  [debug]
  [debug] Sources indirectly invalidated by:
  [debug]     product: Set()
  [debug]     binary dep: Set()
  [debug]     external source: Set()
  [debug] Initially invalidated: Set()
  [debug] Copy resource mappings:
  [debug]
  [debug]
  [debug] Initial source changes:
  [debug]     removed:Set()
  [debug]     added: Set()
  [debug]     modified: Set()
  [debug] Removed products: Set()
  [debug] Modified external sources: Set()
  [debug] Modified binary dependencies: Set()
  [debug] Initial directly invalidated sources: Set()
  [debug]
  [debug] Sources indirectly invalidated by:
  [debug]     product: Set()
  [debug]     binary dep: Set()
  [debug]     external source: Set()
  [debug] Initially invalidated: Set()
  [debug] Copy resource mappings:
  [debug]
  [debug] Framework implementation 'org.scalacheck.ScalaCheckFramework' not present.
  [debug] Framework implementation 'org.specs.runner.SpecsFramework' not present.
  [debug] Framework implementation 'org.scalatest.tools.ScalaTestFramework' not present.
  [debug] Framework implementation 'com.novocode.junit.JUnitFramework' not present.
  [debug] Subclass fingerprints: Stream((org.specs2.specification.SpecificationStructure,false,org.specs2.runner.Fingerprints$$anon$1@34d6488c), ?)
  [debug] Annotation fingerprints: Stream()
  [debug] Running Test ExpandoObjectTest : subclass(false, org.specs2.specification.SpecificationStructure) with arguments
  java.util.concurrent.ExecutionException: java.lang.OutOfMemoryError: PermGen space
      at java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:252)
      at java.util.concurrent.FutureTask.get(FutureTask.java:111)
      at sbt.ConcurrentRestrictions$$anon$4.take(ConcurrentRestrictions.scala:196)
      at sbt.Execute.next$1(Execute.scala:85)
      at sbt.Execute.processAll(Execute.scala:88)
      at sbt.Execute.runKeep(Execute.scala:68)
      at sbt.EvaluateTask$.run$1(EvaluateTask.scala:162)
      at sbt.EvaluateTask$.runTask(EvaluateTask.scala:177)
      at sbt.Aggregation$$anonfun$4.apply(Aggregation.scala:46)
      at sbt.Aggregation$$anonfun$4.apply(Aggregation.scala:44)
      at sbt.EvaluateTask$.withStreams(EvaluateTask.scala:137)
      at sbt.Aggregation$.runTasksWithResult(Aggregation.scala:44)
      at sbt.Aggregation$.runTasks(Aggregation.scala:59)
      at sbt.Aggregation$$anonfun$applyTasks$1.apply(Aggregation.scala:31)
      at sbt.Aggregation$$anonfun$applyTasks$1.apply(Aggregation.scala:30)
      at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:62)
      at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:62)
      at sbt.Command$.process(Command.scala:90)
      at sbt.MainLoop$$anonfun$next$1$$anonfun$apply$1.apply(MainLoop.scala:71)
      at sbt.MainLoop$$anonfun$next$1$$anonfun$apply$1.apply(MainLoop.scala:71)
      at sbt.State$$anon$2.process(State.scala:170)
      at sbt.MainLoop$$anonfun$next$1.apply(MainLoop.scala:71)
      at sbt.MainLoop$$anonfun$next$1.apply(MainLoop.scala:71)
      at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
      at sbt.MainLoop$.next(MainLoop.scala:71)
      at sbt.MainLoop$.run(MainLoop.scala:64)
      at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:53)
      at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:50)
      at sbt.Using.apply(Using.scala:25)
      at sbt.MainLoop$.runWithNewLog(MainLoop.scala:50)
      at sbt.MainLoop$.runAndClearLast(MainLoop.scala:33)
      at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:17)
      at sbt.MainLoop$.runLogged(MainLoop.scala:13)
      at sbt.xMain.run(Main.scala:26)
      at xsbt.boot.Launch$.run(Launch.scala:55)
      at xsbt.boot.Launch$$anonfun$explicit$1.apply(Launch.scala:45)
      at xsbt.boot.Launch$.launch(Launch.scala:69)
      at xsbt.boot.Launch$.apply(Launch.scala:16)
      at xsbt.boot.Boot$.runImpl(Boot.scala:31)
      at xsbt.boot.Boot$.main(Boot.scala:20)
      at xsbt.boot.Boot.main(Boot.scala)
  Caused by: java.lang.OutOfMemoryError: PermGen space
      at java.lang.ClassLoader.defineClass1(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
      at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
      at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
      at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
      at sbt.Project$$anon$5.apply(Project.scala:130)
      at sbt.Project$$anon$5.apply(Project.scala:128)
      at sbt.LogManager$.commandBase$1(LogManager.scala:59)
      at sbt.LogManager$.command$1(LogManager.scala:60)
      at sbt.LogManager$$anonfun$suppressedMessage$1.apply(LogManager.scala:61)
      at sbt.LogManager$$anonfun$suppressedMessage$1.apply(LogManager.scala:61)
      at sbt.ConsoleLogger.trace(ConsoleLogger.scala:163)
      at sbt.AbstractLogger.log(Logger.scala:32)
      at sbt.MultiLogger$$anonfun$dispatch$1.apply(MultiLogger.scala:40)
      at sbt.MultiLogger$$anonfun$dispatch$1.apply(MultiLogger.scala:38)
      at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)
      at scala.collection.immutable.List.foreach(List.scala:76)
      at sbt.MultiLogger.dispatch(MultiLogger.scala:38)
      at sbt.MultiLogger.trace(MultiLogger.scala:30)
      at sbt.TestLogger$$anon$2.trace(TestReportListener.scala:71)
      at sbt.TestLogger.endGroup(TestReportListener.scala:88)
      at sbt.TestRunner$$anonfun$run$5.apply(TestFramework.scala:87)
      at sbt.TestRunner$$anonfun$run$5.apply(TestFramework.scala:87)
      at sbt.TestFramework$$anonfun$safeForeach$1.apply(TestFramework.scala:112)
      at sbt.TestFramework$$anonfun$safeForeach$1.apply(TestFramework.scala:112)
      at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)
  [error] java.util.concurrent.ExecutionException: java.lang.OutOfMemoryError: PermGen space
  [error] Use 'last' for the full log.
  </code></pre>
  
  <p>Sometimes it also exits abruptly with:</p>
  
  <pre><code>sbt appears to be exiting abnormally.
    The log file for this session is at /var/folders/vf/3khb58091wd0_1rz1yh6knb00000gp/T/sbt3242766352271599341.log
  java.lang.OutOfMemoryError: PermGen space
  Error during sbt execution: java.lang.OutOfMemoryError: PermGen space
  </code></pre>
  
  <p>Any solutions?</p>