diff --git a/main-actions/src/main/scala/sbt/compiler/Eval.scala b/main-actions/src/main/scala/sbt/compiler/Eval.scala
index a54d0807b..025dc2810 100644
--- a/main-actions/src/main/scala/sbt/compiler/Eval.scala
+++ b/main-actions/src/main/scala/sbt/compiler/Eval.scala
@@ -1,6 +1,7 @@
 package sbt
 package compiler
 
+import scala.collection.mutable.ListBuffer
 import scala.reflect.Manifest
 import scala.tools.nsc.{ ast, interpreter, io, reporters, util, CompilerCommand, Global, Phase, Settings }
 import io.{ AbstractFile, PlainFile, VirtualDirectory }
@@ -337,14 +338,12 @@ final class Eval(optionsNoncp: Seq[String], classpath: Seq[File], mkReporter: Se
   /** Parses one or more definitions (defs, vals, lazy vals, classes, traits, modules). */
   private[this] def parseDefinitions(parser: syntaxAnalyzer.UnitParser): Seq[Tree] =
     {
-      var defs = parser.nonLocalDefOrDcl
-      parser.acceptStatSepOpt()
-      while (!parser.isStatSeqEnd) {
-        val next = parser.nonLocalDefOrDcl
-        defs ++= next
+      val defs = ListBuffer[Tree]()
+      do {
+        defs ++= parser.nonLocalDefOrDcl
         parser.acceptStatSepOpt()
-      }
-      defs
+      } while (!parser.isStatSeqEnd)
+      defs.toList
     }
 
   private[this] trait EvalType[T] {
diff --git a/run/src/main/scala/sbt/TrapExitSecurityException.scala b/run/src/main/scala/sbt/TrapExitSecurityException.scala
index 50bdab303..dc5792e66 100644
--- a/run/src/main/scala/sbt/TrapExitSecurityException.scala
+++ b/run/src/main/scala/sbt/TrapExitSecurityException.scala
@@ -6,21 +6,10 @@ package sbt
  * terminating the thread's execution.
  */
 private final class TrapExitSecurityException(val exitCode: Int) extends SecurityException {
-  private var accessAllowed = false
-  def allowAccess(): Unit = {
-    accessAllowed = true
-  }
-  override def printStackTrace = ifAccessAllowed(super.printStackTrace)
-  override def toString = ifAccessAllowed(super.toString)
-  override def getCause = ifAccessAllowed(super.getCause)
-  override def getMessage = ifAccessAllowed(super.getMessage)
-  override def fillInStackTrace = ifAccessAllowed(super.fillInStackTrace)
-  override def getLocalizedMessage = ifAccessAllowed(super.getLocalizedMessage)
-  private def ifAccessAllowed[T](f: => T): T =
-    {
-      if (accessAllowed)
-        f
-      else
-        throw this
-    }
+  override def printStackTrace = throw this
+  override def toString = throw this
+  override def getCause = throw this
+  override def getMessage = throw this
+  override def fillInStackTrace = throw this
+  override def getLocalizedMessage = throw this
 }
diff --git a/scripted/sbt/src/main/scala/sbt/test/ScriptedTests.scala b/scripted/sbt/src/main/scala/sbt/test/ScriptedTests.scala
index 0778f9ba7..f341a4925 100644
--- a/scripted/sbt/src/main/scala/sbt/test/ScriptedTests.scala
+++ b/scripted/sbt/src/main/scala/sbt/test/ScriptedTests.scala
@@ -31,7 +31,6 @@ final class ScriptedTests(resourceBaseDirectory: File, bufferLog: Boolean, launc
   def scriptedTest(group: String, name: String, prescripted: File => Unit, log: Logger): Seq[() => Option[String]] = {
     import sbt.io.syntax._
     import GlobFilter._
-    var failed = false
     for (groupDir <- (resourceBaseDirectory * group).get; nme <- (groupDir * name).get) yield {
       val g = groupDir.getName
       val n = nme.getName
diff --git a/tasks/src/main/scala/sbt/Incomplete.scala b/tasks/src/main/scala/sbt/Incomplete.scala
index 5f40193de..a83e33e36 100644
--- a/tasks/src/main/scala/sbt/Incomplete.scala
+++ b/tasks/src/main/scala/sbt/Incomplete.scala
@@ -3,6 +3,8 @@
  */
 package sbt
 
+import scala.collection.mutable.ListBuffer
+
 import sbt.internal.util.IDSet
 import Incomplete.{ Error, Value => IValue }
 
@@ -47,9 +49,9 @@ object Incomplete extends Enumeration {
   }
   def linearize(i: Incomplete): Seq[Incomplete] =
     {
-      var ordered = List[Incomplete]()
-      visitAll(i) { ordered ::= _ }
-      ordered
+      val ordered = ListBuffer[Incomplete]()
+      visitAll(i) { ordered += _ }
+      ordered.toList
     }
   def allExceptions(is: Seq[Incomplete]): Iterable[Throwable] =
     allExceptions(new Incomplete(None, causes = is))