cleaning up a few compiler warnings

main/src/main/scala/sbt/Defaults.scala

@@ -48,7 +48,6 @@ import sbt.io.{
   NothingFilter,
   Path,
   PathFinder,
-  SimpleFileFilter,
   DirectoryFilter,
   Hash
 }, Path._
@@ -2147,7 +2146,7 @@ object Classpaths {
       val report = (updateTask tag (Tags.Update, Tags.Network)).value
       val log = streams.value.log
       val ew =
-        EvictionWarning(ivyModule.value, (evictionWarningOptions in evicted).value, report, log)
+        EvictionWarning(ivyModule.value, (evictionWarningOptions in evicted).value, report)
       ew.lines foreach { log.warn(_) }
       ew.infoAllTheThings foreach { log.info(_) }
       ew
@@ -2222,7 +2221,6 @@ object Classpaths {
       }
     },
     dependencyOverrides ++= {
-      val old = dependencyOverrides.value
       val isPlugin = sbtPlugin.value
       val app = appConfiguration.value
       val id = app.provider.id
@@ -2341,9 +2339,6 @@ object Classpaths {
             val log = s.log
             val out = is.withIvy(log)(_.getSettings.getDefaultIvyUserDir)
             val uwConfig = (unresolvedWarningConfiguration in update).value
-            val depDir = dependencyCacheDirectory.value
-            val ivy = scalaModuleInfo.value
-            val st = state.value
             withExcludes(out, mod.classifiers, lock(app)) {
               excludes =>
                 // val noExplicitCheck = ivy.map(_.withCheckExplicit(false))

main/src/main/scala/sbt/Main.scala

@@ -11,7 +11,6 @@ import sbt.internal.{
   Act,
   Aggregation,
   BuildStructure,
-  BuildUnit,
   CommandExchange,
   CommandStrings,
   CrossJava,
@@ -141,6 +140,7 @@ object StandardMain {
           if (hooked) {
             Runtime.getRuntime.removeShutdownHook(shutdownHook)
           }
+          ()
         }
       } finally DefaultBackgroundJobService.backgroundJobService.shutdown()
     } finally TrapExit.uninstallManager(previous)

main/src/test/scala/PluginCommandTest.scala

@@ -19,7 +19,6 @@ import sbt.internal.util.{
   MainAppender,
   Settings
 }
-import sbt.util.Logger
 
 object PluginCommandTestPlugin0 extends AutoPlugin { override def requires = empty }
 

project/StatusPlugin.scala

@@ -31,7 +31,7 @@ object StatusPlugin extends AutoPlugin {
     val status = extracted.get(publishStatus)
     // Set new version AND lock down the publishStatus to what it was, as
     // our release regexes no longer support ivy data format, due to other issues.
-    extracted.append((version in ThisBuild ~= stamp) ::
+    extracted.appendWithSession((version in ThisBuild ~= stamp) ::
                        (publishStatus in ThisBuild := status) ::
                        Nil,
                      state)