diff --git a/main-actions/src/main/scala/sbt/Package.scala b/main-actions/src/main/scala/sbt/Package.scala
index e0c29e95c..9ce8735b4 100644
--- a/main-actions/src/main/scala/sbt/Package.scala
+++ b/main-actions/src/main/scala/sbt/Package.scala
@@ -22,7 +22,7 @@ import sbt.internal.util.HNil
 import sbt.internal.util.HListFormats._
 import sbt.util.FileInfo.{ exists, lastModified }
 import sbt.util.CacheImplicits._
-import sbt.util.Tracked.inputChanged
+import sbt.util.Tracked.{ inputChanged, outputChanged }
 
 sealed trait PackageOption
 object Package {
@@ -72,17 +72,18 @@ object Package {
       (inChanged, inputs: Inputs) =>
         import exists.format
         val sources :+: _ :+: manifest :+: HNil = inputs
-        inputChanged(cacheStoreFactory make "output") { (outChanged, jar: PlainFileInfo) =>
-          if (inChanged || outChanged)
+        outputChanged(cacheStoreFactory make "output") { (outChanged, jar: PlainFileInfo) =>
+          if (inChanged || outChanged) {
             makeJar(sources.toSeq, jar.file, manifest, log)
-          else
+            jar.file
+          } else
             log.debug("Jar uptodate: " + jar.file)
         }
     }
 
     val map = conf.sources.toMap
     val inputs = map :+: lastModified(map.keySet) :+: manifest :+: HNil
-    cachedMakeJar(inputs)(exists(conf.jar))
+    cachedMakeJar(inputs)(() => exists(conf.jar))
   }
   def setVersion(main: Attributes): Unit = {
     val version = Attributes.Name.MANIFEST_VERSION
diff --git a/main-command/src/main/scala/sbt/BasicCommandStrings.scala b/main-command/src/main/scala/sbt/BasicCommandStrings.scala
index b819f77a5..482612f6f 100644
--- a/main-command/src/main/scala/sbt/BasicCommandStrings.scala
+++ b/main-command/src/main/scala/sbt/BasicCommandStrings.scala
@@ -69,7 +69,7 @@ $HelpCommand <regular expression>
 	This will be used as the default level for logging from commands, settings, and tasks.
 	Any explicit `logLevel` configuration in a project overrides this setting.
 
--$level
+-$level OR --$level
 
 	Sets the global logging level as described above, but does so before any other commands are executed on startup, including project loading.
 	This is useful as a startup option:
@@ -79,7 +79,9 @@ $HelpCommand <regular expression>
 
   def runEarly(command: String) = s"$EarlyCommand($command)"
   private[sbt] def isEarlyCommand(s: String): Boolean = {
-    val levelOptions = Level.values.toSeq map { "-" + _ }
+    val levelOptions = Level.values.toSeq flatMap { elem =>
+      List("-" + elem, "--" + elem)
+    }
     (s.startsWith(EarlyCommand + "(") && s.endsWith(")")) ||
     (levelOptions contains s)
   }
diff --git a/main-command/src/main/scala/sbt/BasicCommands.scala b/main-command/src/main/scala/sbt/BasicCommands.scala
index 439821a6d..eee6311ac 100644
--- a/main-command/src/main/scala/sbt/BasicCommands.scala
+++ b/main-command/src/main/scala/sbt/BasicCommands.scala
@@ -69,7 +69,8 @@ object BasicCommands {
   private[this] def earlyParser: State => Parser[String] = (s: State) => {
     val p1 = token(EarlyCommand + "(") flatMap (_ => otherCommandParser(s) <~ token(")"))
     val p2 = token("-") flatMap (_ => levelParser)
-    p1 | p2
+    val p3 = token("--") flatMap (_ => levelParser)
+    p1 | p2 | p3
   }
 
   private[this] def earlyHelp = Help(EarlyCommand, EarlyCommandBrief, EarlyCommandDetailed)
diff --git a/main-command/src/main/scala/sbt/Watched.scala b/main-command/src/main/scala/sbt/Watched.scala
index eed2b60a0..053e15082 100644
--- a/main-command/src/main/scala/sbt/Watched.scala
+++ b/main-command/src/main/scala/sbt/Watched.scala
@@ -12,7 +12,7 @@ import java.nio.file.FileSystems
 
 import sbt.BasicCommandStrings.ClearOnFailure
 import sbt.State.FailureWall
-import sbt.internal.io.{ Source, SourceModificationWatch, WatchState }
+import sbt.internal.io.{ EventMonitor, Source, WatchState }
 import sbt.internal.util.AttributeKey
 import sbt.internal.util.Types.const
 import sbt.io._
@@ -33,6 +33,12 @@ trait Watched {
    */
   def pollInterval: FiniteDuration = Watched.PollDelay
 
+  /**
+   * The duration for which the EventMonitor while ignore file events after a file triggers
+   * a new build.
+   */
+  def antiEntropy: FiniteDuration = Watched.AntiEntropy
+
   /** The message to show when triggered execution waits for sources to change.*/
   private[sbt] def watchingMessage(s: WatchState): String = Watched.defaultWatchingMessage(s)
 
@@ -86,53 +92,70 @@ object Watched {
       override def watchSources(s: State) = (base.watchSources(s) /: paths)(_ ++ _.watchSources(s))
       override def terminateWatch(key: Int): Boolean = base.terminateWatch(key)
       override val pollInterval = (base +: paths).map(_.pollInterval).min
+      override val antiEntropy = (base +: paths).map(_.antiEntropy).min
       override def watchingMessage(s: WatchState) = base.watchingMessage(s)
       override def triggeredMessage(s: WatchState) = base.triggeredMessage(s)
     }
   def empty: Watched = new AWatched
 
   val PollDelay: FiniteDuration = 500.milliseconds
+  val AntiEntropy: FiniteDuration = 40.milliseconds
   def isEnter(key: Int): Boolean = key == 10 || key == 13
   def printIfDefined(msg: String) = if (!msg.isEmpty) System.out.println(msg)
 
   def executeContinuously(watched: Watched, s: State, next: String, repeat: String): State = {
     @tailrec def shouldTerminate: Boolean =
       (System.in.available > 0) && (watched.terminateWatch(System.in.read()) || shouldTerminate)
-    val sources = watched.watchSources(s)
-    val service = s get ContinuousWatchService getOrElse watched.watchService()
-    val watchState = s get ContinuousState getOrElse WatchState.empty(service, sources)
-
-    if (watchState.count > 0)
-      printIfDefined(watched watchingMessage watchState)
-
-    val (triggered, newWatchState) =
-      try {
-        val (triggered, newWatchState) =
-          SourceModificationWatch.watch(watched.pollInterval, watchState)(shouldTerminate)
-        (triggered, newWatchState)
-      } catch {
-        case e: Exception =>
-          s.log.error(
-            "Error occurred obtaining files to watch.  Terminating continuous execution..."
+    val log = s.log
+    val logger = new EventMonitor.Logger {
+      override def debug(msg: => Any): Unit = log.debug(msg.toString)
+    }
+    s get ContinuousEventMonitor match {
+      case None =>
+        // This is the first iteration, so run the task and create a new EventMonitor
+        (ClearOnFailure :: next :: FailureWall :: repeat :: s)
+          .put(
+            ContinuousEventMonitor,
+            EventMonitor(
+              WatchState.empty(watched.watchService(), watched.watchSources(s)),
+              watched.pollInterval,
+              watched.antiEntropy,
+              shouldTerminate,
+              logger
+            )
           )
-          s.handleError(e)
-          (false, watchState)
-      }
-
-    if (triggered) {
-      printIfDefined(watched triggeredMessage newWatchState)
-      (ClearOnFailure :: next :: FailureWall :: repeat :: s)
-        .put(ContinuousState, newWatchState)
-        .put(ContinuousWatchService, service)
-    } else {
-      while (System.in.available() > 0) System.in.read()
-      service.close()
-      s.remove(ContinuousState).remove(ContinuousWatchService)
+      case Some(eventMonitor) =>
+        printIfDefined(watched watchingMessage eventMonitor.state)
+        val triggered = try eventMonitor.awaitEvent()
+        catch {
+          case e: Exception =>
+            log.error(
+              "Error occurred obtaining files to watch.  Terminating continuous execution..."
+            )
+            s.handleError(e)
+            false
+        }
+        if (triggered) {
+          printIfDefined(watched triggeredMessage eventMonitor.state)
+          ClearOnFailure :: next :: FailureWall :: repeat :: s
+        } else {
+          while (System.in.available() > 0) System.in.read()
+          eventMonitor.close()
+          s.remove(ContinuousEventMonitor)
+        }
     }
   }
+
+  val ContinuousEventMonitor =
+    AttributeKey[EventMonitor](
+      "watch event monitor",
+      "Internal: maintains watch state and monitor threads."
+    )
+  @deprecated("Superseded by ContinuousEventMonitor", "1.1.5")
   val ContinuousState =
     AttributeKey[WatchState]("watch state", "Internal: tracks state for continuous execution.")
 
+  @deprecated("Superseded by ContinuousEventMonitor", "1.1.5")
   val ContinuousWatchService =
     AttributeKey[WatchService](
       "watch service",
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index f3e550205..d8c072cae 100755
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -259,6 +259,7 @@ object Defaults extends BuildCommon {
       concurrentRestrictions := defaultRestrictions.value,
       parallelExecution :== true,
       pollInterval :== new FiniteDuration(500, TimeUnit.MILLISECONDS),
+      watchAntiEntropy :== new FiniteDuration(40, TimeUnit.MILLISECONDS),
       watchService :== { () =>
         Watched.createWatchService()
       },
@@ -352,7 +353,18 @@ object Defaults extends BuildCommon {
       val baseDir = baseDirectory.value
       val bases = unmanagedSourceDirectories.value
       val include = (includeFilter in unmanagedSources).value
-      val exclude = (excludeFilter in unmanagedSources).value
+      val exclude = (excludeFilter in unmanagedSources).value match {
+        case e =>
+          (managedSources in ThisScope).value match {
+            case l if l.nonEmpty =>
+              e || new FileFilter {
+                private val files = l.toSet
+                override def accept(pathname: File): Boolean = files.contains(pathname)
+                override def toString = s"ManagedSourcesFilter($files)"
+              }
+            case _ => e
+          }
+      }
       val baseSources =
         if (sourcesInBase.value) Seq(new Source(baseDir, include, exclude, recursive = false))
         else Nil
@@ -364,7 +376,7 @@ object Defaults extends BuildCommon {
     sourceDirectories := Classpaths
       .concatSettings(unmanagedSourceDirectories, managedSourceDirectories)
       .value,
-    sources := Classpaths.concat(unmanagedSources, managedSources).value
+    sources := Classpaths.concatDistinct(unmanagedSources, managedSources).value
   )
   lazy val resourceConfigPaths = Seq(
     resourceDirectory := sourceDirectory.value / "resources",
@@ -593,13 +605,15 @@ object Defaults extends BuildCommon {
     Def.setting {
       val getService = watchService.value
       val interval = pollInterval.value
+      val _antiEntropy = watchAntiEntropy.value
       val base = thisProjectRef.value
       val msg = watchingMessage.value
       val trigMsg = triggeredMessage.value
       new Watched {
         val scoped = watchTransitiveSources in base
         val key = scoped.scopedKey
-        override def pollInterval = interval
+        override def antiEntropy: FiniteDuration = _antiEntropy
+        override def pollInterval: FiniteDuration = interval
         override def watchingMessage(s: WatchState) = msg(s)
         override def triggeredMessage(s: WatchState) = trigMsg(s)
         override def watchService() = getService()
@@ -3052,10 +3066,21 @@ object Classpaths {
       excl: FileFilter
   ): Classpath =
     (base * (filter -- excl) +++ (base / config.name).descendantsExcept(filter, excl)).classpath
+  @deprecated(
+    "The method only works for Scala 2, use the overloaded version to support both Scala 2 and Scala 3",
+    "1.1.5"
+  )
+  def autoPlugins(report: UpdateReport, internalPluginClasspath: Seq[File]): Seq[String] =
+    autoPlugins(report, internalPluginClasspath, isDotty = false)
 
-  def autoPlugins(report: UpdateReport, internalPluginClasspath: Seq[File]): Seq[String] = {
+  def autoPlugins(
+      report: UpdateReport,
+      internalPluginClasspath: Seq[File],
+      isDotty: Boolean
+  ): Seq[String] = {
     val pluginClasspath = report.matching(configurationFilter(CompilerPlugin.name)) ++ internalPluginClasspath
-    val plugins = sbt.internal.inc.classpath.ClasspathUtilities.compilerPlugins(pluginClasspath)
+    val plugins =
+      sbt.internal.inc.classpath.ClasspathUtilities.compilerPlugins(pluginClasspath, isDotty)
     plugins.map("-Xplugin:" + _.getAbsolutePath).toSeq
   }
 
@@ -3077,7 +3102,11 @@ object Classpaths {
   lazy val compilerPluginConfig = Seq(
     scalacOptions := {
       val options = scalacOptions.value
-      val newPlugins = autoPlugins(update.value, internalCompilerPluginClasspath.value.files)
+      val newPlugins = autoPlugins(
+        update.value,
+        internalCompilerPluginClasspath.value.files,
+        ScalaInstance.isDotty(scalaVersion.value)
+      )
       val existing = options.toSet
       if (autoCompilerPlugins.value) options ++ newPlugins.filterNot(existing) else options
     }
diff --git a/main/src/main/scala/sbt/Keys.scala b/main/src/main/scala/sbt/Keys.scala
index bf8c9549f..45d9c2d96 100644
--- a/main/src/main/scala/sbt/Keys.scala
+++ b/main/src/main/scala/sbt/Keys.scala
@@ -143,6 +143,7 @@ object Keys {
   val analysis = AttributeKey[CompileAnalysis]("analysis", "Analysis of compilation, including dependencies and generated outputs.", DSetting)
   val watch = SettingKey(BasicKeys.watch)
   val suppressSbtShellNotification = settingKey[Boolean]("""True to suppress the "Executing in batch mode.." message.""").withRank(CSetting)
+  val watchAntiEntropy = settingKey[FiniteDuration]("Duration for which the watch EventMonitor will ignore events for a file after that file has triggered a build.").withRank(BMinusSetting)
   val pollInterval = settingKey[FiniteDuration]("Interval between checks for modified sources by the continuous execution command.").withRank(BMinusSetting)
   val watchService = settingKey[() => WatchService]("Service to use to monitor file system changes.").withRank(BMinusSetting)
   val watchSources = taskKey[Seq[Watched.WatchSource]]("Defines the sources in this project for continuous execution to watch for changes.").withRank(BMinusSetting)
diff --git a/main/src/main/scala/sbt/Main.scala b/main/src/main/scala/sbt/Main.scala
index d6185d41e..86a02db6b 100644
--- a/main/src/main/scala/sbt/Main.scala
+++ b/main/src/main/scala/sbt/Main.scala
@@ -328,8 +328,14 @@ object BuiltinCommands {
       'v'.id.+.map(_.size + 1) |
         ("V" ^^^ Int.MaxValue)
     ))
+
+  def taskDetail(keys: Seq[AttributeKey[_]], firstOnly: Boolean): Seq[(String, String)] =
+    sortByLabel(withDescription(keys)) flatMap { t =>
+      taskStrings(t, firstOnly)
+    }
+
   def taskDetail(keys: Seq[AttributeKey[_]]): Seq[(String, String)] =
-    sortByLabel(withDescription(keys)) flatMap taskStrings
+    taskDetail(keys, false)
 
   def allTaskAndSettingKeys(s: State): Seq[AttributeKey[_]] = {
     val extracted = Project.extract(s)
@@ -367,16 +373,19 @@ object BuiltinCommands {
       filter: Seq[AttributeKey[_]] => Seq[AttributeKey[_]],
       arg: Option[String]
   ): String = {
-    val commandAndDescription = taskDetail(filter(allTaskAndSettingKeys(s)))
+    val commandAndDescription = taskDetail(filter(allTaskAndSettingKeys(s)), true)
     arg match {
       case Some(selected) => detail(selected, commandAndDescription.toMap)
       case None           => aligned("  ", "   ", commandAndDescription) mkString ("\n", "\n", "")
     }
   }
 
-  def taskStrings(key: AttributeKey[_]): Option[(String, String)] = key.description map { d =>
-    (key.label, d)
-  }
+  def taskStrings(key: AttributeKey[_], firstOnly: Boolean): Option[(String, String)] =
+    key.description map { d =>
+      if (firstOnly) (key.label, d.split("\r?\n")(0)) else (key.label, d)
+    }
+
+  def taskStrings(key: AttributeKey[_]): Option[(String, String)] = taskStrings(key, false)
 
   def defaults = Command.command(DefaultsCommand) { s =>
     s.copy(definedCommands = DefaultCommands)
diff --git a/main/src/main/scala/sbt/internal/parser/SbtParser.scala b/main/src/main/scala/sbt/internal/parser/SbtParser.scala
index fa427ec92..2b170b570 100644
--- a/main/src/main/scala/sbt/internal/parser/SbtParser.scala
+++ b/main/src/main/scala/sbt/internal/parser/SbtParser.scala
@@ -151,7 +151,9 @@ private[sbt] object SbtParser {
     reporter.reset()
     val wrapperFile = new BatchSourceFile(reporterId, code)
     val unit = new CompilationUnit(wrapperFile)
-    val parser = new syntaxAnalyzer.UnitParser(unit)
+    val parser = SbtParser.synchronized { // see https://github.com/sbt/sbt/issues/4148
+      new syntaxAnalyzer.UnitParser(unit)
+    }
     val parsedTrees = SbtParser.synchronized { // see https://github.com/scala/bug/issues/10605
       parser.templateStats()
     }
diff --git a/notes/1.1.5/dotty-plugin.md b/notes/1.1.5/dotty-plugin.md
new file mode 100644
index 000000000..6250c30dd
--- /dev/null
+++ b/notes/1.1.5/dotty-plugin.md
@@ -0,0 +1,9 @@
+[@liufengyun]: https://github.com/liufengyun
+
+[4073]: https://github.com/sbt/sbt/issues/4073
+[4084]: https://github.com/sbt/sbt/pull/4084
+
+
+### Improvements
+
+- Detect dotty plugins which have descriptor file named `plugin.properties` instead of `scalac-plugin.xml`.  [#4073][4073]/[#4084][4084] by [@liufengyun][@liufengyun]
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index b1e9fd0ab..bb2a81649 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -8,10 +8,10 @@ object Dependencies {
   val baseScalaVersion = scala212
 
   // sbt modules
-  private val ioVersion = "1.1.6"
+  private val ioVersion = "1.1.10"
   private val utilVersion = "1.1.3"
-  private val lmVersion = "1.1.4"
-  private val zincVersion = "1.1.5"
+  private val lmVersion = "1.1.5"
+  private val zincVersion = "1.1.7"
 
   private val sbtIO = "org.scala-sbt" %% "io" % ioVersion
 
diff --git a/sbt/src/sbt-test/actions/early-command/test b/sbt/src/sbt-test/actions/early-command/test
index 532cef013..66e241ad4 100644
--- a/sbt/src/sbt-test/actions/early-command/test
+++ b/sbt/src/sbt-test/actions/early-command/test
@@ -1,2 +1,3 @@
 > -error
 > early(error)
+> --error
\ No newline at end of file
diff --git a/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/build.sbt b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/build.sbt
new file mode 100644
index 000000000..099cd9f71
--- /dev/null
+++ b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/build.sbt
@@ -0,0 +1,16 @@
+// hardcode dottyVersion to make test deterministic
+lazy val dottyVersion = "0.8.0-bin-20180424-e77604d-NIGHTLY"
+
+lazy val plugin = (project in file("plugin"))
+  .settings(
+    name := "dividezero",
+    version := "0.0.1",
+    organization := "ch.epfl.lamp",
+    scalaVersion := dottyVersion,
+  )
+
+lazy val app = (project in file("."))
+  .settings(
+    scalaVersion := dottyVersion,
+    libraryDependencies += compilerPlugin("ch.epfl.lamp" %% "dividezero" % "0.0.1"),
+  )
diff --git a/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/plugin/DivideZero.scala b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/plugin/DivideZero.scala
new file mode 100644
index 000000000..c110a7cee
--- /dev/null
+++ b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/plugin/DivideZero.scala
@@ -0,0 +1,40 @@
+package dividezero
+
+import dotty.tools.dotc._
+import core._
+import Contexts.Context
+import plugins._
+import Phases.Phase
+import ast.tpd
+import transform.MegaPhase.MiniPhase
+import Decorators._
+import Symbols.Symbol
+import Constants.Constant
+import transform.{LinkAll, Pickler}
+
+class DivideZero extends PluginPhase with StandardPlugin {
+  val name: String = "divideZero"
+  override val description: String = "divide zero check"
+
+  val phaseName = name
+
+  override val runsAfter = Set(Pickler.name)
+  override val runsBefore = Set(LinkAll.name)
+
+  override def init(options: List[String]): List[PluginPhase] = this :: Nil
+
+  private def isNumericDivide(sym: Symbol)(implicit ctx: Context): Boolean = {
+    def test(tpe: String): Boolean =
+      (sym.owner eq ctx.requiredClass(tpe.toTermName)) && sym.name.show == "/"
+
+    test("scala.Int") || test("scala.Long") || test("scala.Short") || test("scala.Float") || test("scala.Double")
+  }
+
+  override def transformApply(tree: tpd.Apply)(implicit ctx: Context): tpd.Tree = tree match {
+    case tpd.Apply(fun, tpd.Literal(Constants.Constant(v)) :: Nil) if isNumericDivide(fun.symbol) && v == 0 =>
+      ctx.warning("divide by zero", tree.pos)
+      tpd.Literal(Constant(0))
+    case _ =>
+      tree
+  }
+}
diff --git a/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/plugin/src/main/resources/plugin.properties b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/plugin/src/main/resources/plugin.properties
new file mode 100644
index 000000000..db215842c
--- /dev/null
+++ b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/plugin/src/main/resources/plugin.properties
@@ -0,0 +1 @@
+pluginClass=dividezero.DivideZero
\ No newline at end of file
diff --git a/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/project/plugins.sbt b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/project/plugins.sbt
new file mode 100644
index 000000000..ba89aa2bb
--- /dev/null
+++ b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/project/plugins.sbt
@@ -0,0 +1 @@
+addSbtPlugin("ch.epfl.lamp" % "sbt-dotty" % "0.2.0")
diff --git a/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/src/main/scala/hello/Hello.scala b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/src/main/scala/hello/Hello.scala
new file mode 100644
index 000000000..99ae2d0d7
--- /dev/null
+++ b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/src/main/scala/hello/Hello.scala
@@ -0,0 +1,13 @@
+package hello
+object Hello {
+  def main(args: Array[String]): Unit = {
+    val dotty: Int | String = "dotty"
+
+    val y = 5 / 0 // error
+    100 + 6 / 0 // error
+    6L / 0L // error
+    val z = 7 / 0.0 // error
+
+    println(s"Hello $dotty!")
+  }
+}
diff --git a/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/test b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/test
new file mode 100644
index 000000000..28c06d4d6
--- /dev/null
+++ b/sbt/src/sbt-test/compiler-project/dotty-compiler-plugin/test
@@ -0,0 +1,2 @@
+> plugin/publishLocal
+> app/run
diff --git a/sbt/src/sbt-test/tests/watch-loop/build.sbt b/sbt/src/sbt-test/tests/watch-loop/build.sbt
new file mode 100644
index 000000000..effea2c79
--- /dev/null
+++ b/sbt/src/sbt-test/tests/watch-loop/build.sbt
@@ -0,0 +1,17 @@
+import java.nio.file.Files
+
+lazy val watchLoopTest = taskKey[Unit]("Check that managed sources are filtered")
+
+sourceGenerators in Compile += Def.task {
+  val path = baseDirectory.value.toPath.resolve("src/main/scala/Foo.scala")
+  Files.write(path, "object Foo".getBytes).toFile :: Nil
+}
+
+watchLoopTest := {
+  val watched = watchSources.value
+  val managedSource = (managedSources in Compile).value.head
+  assert(!SourceWrapper.accept(watched, managedSource))
+  assert((sources in Compile).value.foldLeft((true, Set.empty[File])) {
+    case ((res, set), f) => (res && !set.contains(f), set + f)
+  }._1)
+}
diff --git a/sbt/src/sbt-test/tests/watch-loop/project/SourceWrapper.scala b/sbt/src/sbt-test/tests/watch-loop/project/SourceWrapper.scala
new file mode 100644
index 000000000..ff351168a
--- /dev/null
+++ b/sbt/src/sbt-test/tests/watch-loop/project/SourceWrapper.scala
@@ -0,0 +1,6 @@
+package sbt
+
+object SourceWrapper {
+  def accept(sources: Seq[sbt.internal.io.Source], file: File): Boolean =
+    sources.exists(_.accept(file.toPath))
+}
diff --git a/sbt/src/sbt-test/tests/watch-loop/src/main/scala/Bar.scala b/sbt/src/sbt-test/tests/watch-loop/src/main/scala/Bar.scala
new file mode 100644
index 000000000..3b43dece6
--- /dev/null
+++ b/sbt/src/sbt-test/tests/watch-loop/src/main/scala/Bar.scala
@@ -0,0 +1 @@
+object Bar
diff --git a/sbt/src/sbt-test/tests/watch-loop/src/main/scala/Foo.scala b/sbt/src/sbt-test/tests/watch-loop/src/main/scala/Foo.scala
new file mode 100644
index 000000000..d37c10456
--- /dev/null
+++ b/sbt/src/sbt-test/tests/watch-loop/src/main/scala/Foo.scala
@@ -0,0 +1 @@
+object Foo
\ No newline at end of file
diff --git a/sbt/src/sbt-test/tests/watch-loop/test b/sbt/src/sbt-test/tests/watch-loop/test
new file mode 100644
index 000000000..41d621982
--- /dev/null
+++ b/sbt/src/sbt-test/tests/watch-loop/test
@@ -0,0 +1 @@
+> watchLoopTest
diff --git a/scripted/sbt/src/main/scala/sbt/scriptedtest/ScriptedTests.scala b/scripted/sbt/src/main/scala/sbt/scriptedtest/ScriptedTests.scala
index 77e3b7467..50883790e 100644
--- a/scripted/sbt/src/main/scala/sbt/scriptedtest/ScriptedTests.scala
+++ b/scripted/sbt/src/main/scala/sbt/scriptedtest/ScriptedTests.scala
@@ -167,6 +167,7 @@ final class ScriptedTests(
       case "actions/external-doc"                                   => LauncherBased // sbt/Package$
       case "actions/input-task"                                     => LauncherBased // sbt/Package$
       case "actions/input-task-dyn"                                 => LauncherBased // sbt/Package$
+      case "compiler-project/dotty-compiler-plugin"                 => LauncherBased // sbt/Package$
       case "compiler-project/run-test"                              => LauncherBased // sbt/Package$
       case "compiler-project/src-dep-plugin"                        => LauncherBased // sbt/Package$
       case "dependency-management/artifact"                         => LauncherBased // tbd