diff --git a/build.sbt b/build.sbt
index bb6df2c9d0..5e50c04aad 100644
--- a/build.sbt
+++ b/build.sbt
@@ -203,6 +203,24 @@ lazy val testingProj = (project in file("testing"))
     sourceManaged in (Compile, generateContrabands) := baseDirectory.value / "src" / "main" / "contraband-scala",
     contrabandFormatsForType in generateContrabands in Compile := ContrabandConfig.getFormats,
     mimaSettings,
+    mimaBinaryIssueFilters ++= Seq(
+      // copy method was never meant to be public
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.EndTestGroupErrorEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.EndTestGroupErrorEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.EndTestGroupEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.EndTestGroupEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.StartTestGroupEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.StartTestGroupEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestCompleteEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestCompleteEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestInitEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestItemDetail.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestItemDetail.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestItemEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestItemEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestStringEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.testing.TestStringEvent.copy$default$1"),
+    )
   )
   .configure(addSbtIO, addSbtCompilerClasspath, addSbtUtilLogging)
 
@@ -251,6 +269,17 @@ lazy val runProj = (project in file("run"))
       baseDirectory.value / "src" / "main" / "contraband-scala",
     sourceManaged in (Compile, generateContrabands) := baseDirectory.value / "src" / "main" / "contraband-scala",
     mimaSettings,
+    mimaBinaryIssueFilters ++= Seq(
+      // copy method was never meant to be public
+      exclude[DirectMissingMethodProblem]("sbt.ForkOptions.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.ForkOptions.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.OutputStrategy#BufferedOutput.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.OutputStrategy#BufferedOutput.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.OutputStrategy#CustomOutput.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.OutputStrategy#CustomOutput.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.OutputStrategy#LoggedOutput.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.OutputStrategy#LoggedOutput.copy$default$*"),
+    )
   )
   .configure(addSbtIO, addSbtUtilLogging, addSbtCompilerClasspath)
 
@@ -307,6 +336,31 @@ lazy val protocolProj = (project in file("protocol"))
     sourceManaged in (Compile, generateContrabands) := baseDirectory.value / "src" / "main" / "contraband-scala",
     contrabandFormatsForType in generateContrabands in Compile := ContrabandConfig.getFormats,
     mimaSettings,
+    mimaBinaryIssueFilters ++= Seq(
+      // copy method was never meant to be public
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ChannelAcceptedEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ChannelAcceptedEvent.copy$default$1"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecCommand.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecCommand.copy$default$1"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecCommand.copy$default$2"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecStatusEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecStatusEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecutionEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.ExecutionEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.InitCommand.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.InitCommand.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.LogEvent.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.LogEvent.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.SettingQuery.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.SettingQuery.copy$default$1"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.SettingQueryFailure.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.SettingQueryFailure.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.SettingQuerySuccess.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.protocol.SettingQuerySuccess.copy$default$*"),
+
+      // ignore missing methods in sbt.internal
+      exclude[DirectMissingMethodProblem]("sbt.internal.*"),
+    )
   )
   .configure(addSbtUtilLogging)
 
@@ -336,6 +390,12 @@ lazy val commandProj = (project in file("main-command"))
       // Replace nailgun socket stuff
       exclude[MissingClassProblem]("sbt.internal.NG*"),
       exclude[MissingClassProblem]("sbt.internal.ReferenceCountedFileDescriptor"),
+
+      // copy method was never meant to be public
+      exclude[DirectMissingMethodProblem]("sbt.CommandSource.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.CommandSource.copy$default$*"),
+      exclude[DirectMissingMethodProblem]("sbt.Exec.copy"),
+      exclude[DirectMissingMethodProblem]("sbt.Exec.copy$default$*"),
     ),
     unmanagedSources in (Compile, headerCreate) := {
       val old = (unmanagedSources in (Compile, headerCreate)).value
diff --git a/main-command/src/main/contraband-scala/sbt/CommandSource.scala b/main-command/src/main/contraband-scala/sbt/CommandSource.scala
index e57e918579..b15193ab1a 100644
--- a/main-command/src/main/contraband-scala/sbt/CommandSource.scala
+++ b/main-command/src/main/contraband-scala/sbt/CommandSource.scala
@@ -19,7 +19,7 @@ final class CommandSource private (
   override def toString: String = {
     "CommandSource(" + channelName + ")"
   }
-  protected[this] def copy(channelName: String = channelName): CommandSource = {
+  private[this] def copy(channelName: String = channelName): CommandSource = {
     new CommandSource(channelName)
   }
   def withChannelName(channelName: String): CommandSource = {
diff --git a/main-command/src/main/contraband-scala/sbt/Exec.scala b/main-command/src/main/contraband-scala/sbt/Exec.scala
index 829c885aea..5b5398bff7 100644
--- a/main-command/src/main/contraband-scala/sbt/Exec.scala
+++ b/main-command/src/main/contraband-scala/sbt/Exec.scala
@@ -21,7 +21,7 @@ final class Exec private (
   override def toString: String = {
     "Exec(" + commandLine + ", " + execId + ", " + source + ")"
   }
-  protected[this] def copy(commandLine: String = commandLine, execId: Option[String] = execId, source: Option[sbt.CommandSource] = source): Exec = {
+  private[this] def copy(commandLine: String = commandLine, execId: Option[String] = execId, source: Option[sbt.CommandSource] = source): Exec = {
     new Exec(commandLine, execId, source)
   }
   def withCommandLine(commandLine: String): Exec = {
@@ -42,8 +42,8 @@ final class Exec private (
 }
 object Exec {
   def newExecId: String = java.util.UUID.randomUUID.toString
-  def apply(commandLine: String, source: Option[sbt.CommandSource]): Exec = new Exec(commandLine, None, source)
-  def apply(commandLine: String, source: sbt.CommandSource): Exec = new Exec(commandLine, None, Option(source))
+  def apply(commandLine: String, source: Option[sbt.CommandSource]): Exec = new Exec(commandLine, source)
+  def apply(commandLine: String, source: sbt.CommandSource): Exec = new Exec(commandLine, Option(source))
   def apply(commandLine: String, execId: Option[String], source: Option[sbt.CommandSource]): Exec = new Exec(commandLine, execId, source)
   def apply(commandLine: String, execId: String, source: sbt.CommandSource): Exec = new Exec(commandLine, Option(execId), Option(source))
 }
diff --git a/main-command/src/main/scala/sbt/internal/server/Server.scala b/main-command/src/main/scala/sbt/internal/server/Server.scala
index 05b86c48a5..c2bccb886f 100644
--- a/main-command/src/main/scala/sbt/internal/server/Server.scala
+++ b/main-command/src/main/scala/sbt/internal/server/Server.scala
@@ -63,7 +63,8 @@ private[sbt] object Server {
                 val maxSocketLength = new UnixDomainSocketLibrary.SockaddrUn().sunPath.length - 1
                 val path = socketfile.getAbsolutePath
                 if (path.length > maxSocketLength)
-                  sys.error("socket file absolute path too long; " +
+                  sys.error(
+                    "socket file absolute path too long; " +
                       "either switch to another connection type " +
                       "or define a short \"SBT_GLOBAL_SERVER_DIR\" value. " +
                       s"Current path: ${path}")
diff --git a/main/src/main/scala/sbt/MainLoop.scala b/main/src/main/scala/sbt/MainLoop.scala
index 83b38b4c8a..2ff80e17e0 100644
--- a/main/src/main/scala/sbt/MainLoop.scala
+++ b/main/src/main/scala/sbt/MainLoop.scala
@@ -15,6 +15,7 @@ import jline.TerminalFactory
 import sbt.io.{ IO, Using }
 import sbt.internal.util.{ ErrorHandling, GlobalLogBacking }
 import sbt.internal.util.complete.DefaultParsers
+import sbt.internal.langserver.ErrorCodes
 import sbt.util.Logger
 import sbt.protocol._
 
@@ -155,13 +156,63 @@ object MainLoop {
         state.log error errMsg
         state.fail
     }
-    StandardMain.exchange publishEventMessage ExecStatusEvent(
+    val doneEvent = ExecStatusEvent(
       "Done",
       channelName,
       exec.execId,
-      newState.remainingCommands.toVector map (_.commandLine))
+      newState.remainingCommands.toVector map (_.commandLine),
+      exitCode(newState, state),
+    )
+    if (doneEvent.execId.isDefined) { // send back a response or error
+      import sbt.protocol.codec.JsonProtocol._
+      StandardMain.exchange publishEvent doneEvent
+    } else { // send back a notification
+      StandardMain.exchange publishEventMessage doneEvent
+    }
     newState
   }
 
   def logFullException(e: Throwable, log: Logger): Unit = State.logFullException(e, log)
+
+  private[this] type ExitCode = Option[Long]
+  private[this] object ExitCode {
+    def apply(n: Long): ExitCode = Option(n)
+    val Success: ExitCode = ExitCode(0)
+    val Unknown: ExitCode = None
+  }
+
+  private[this] def exitCode(state: State, prevState: State): ExitCode = {
+    exitCodeFromStateNext(state) match {
+      case ExitCode.Success => exitCodeFromStateOnFailure(state, prevState)
+      case x                => x
+    }
+  }
+
+  // State's "next" field indicates the next action for the command processor to take
+  // we'll use that to determine if the command failed
+  private[this] def exitCodeFromStateNext(state: State): ExitCode = {
+    state.next match {
+      case State.Continue       => ExitCode.Success
+      case State.ClearGlobalLog => ExitCode.Success
+      case State.KeepLastLog    => ExitCode.Success
+      case ret: State.Return =>
+        ret.result match {
+          case exit: xsbti.Exit  => ExitCode(exit.code().toLong)
+          case _: xsbti.Continue => ExitCode.Success
+          case _: xsbti.Reboot   => ExitCode.Success
+          case x =>
+            val clazz = if (x eq null) "" else " (class: " + x.getClass + ")"
+            state.log debug s"Unknown main result: $x$clazz"
+            ExitCode.Unknown
+        }
+    }
+  }
+
+  // the shell command specifies an onFailure so that if an exception is thrown
+  // it's handled by executing the shell again, instead of the state failing
+  // so we also use that to indicate that the execution failed
+  private[this] def exitCodeFromStateOnFailure(state: State, prevState: State): ExitCode =
+    if (prevState.onFailure.isDefined && state.onFailure.isEmpty) ExitCode(ErrorCodes.UnknownError)
+    else ExitCode.Success
+
 }
diff --git a/main/src/main/scala/sbt/internal/server/NetworkChannel.scala b/main/src/main/scala/sbt/internal/server/NetworkChannel.scala
index 7c27063dea..f8dfdf7842 100644
--- a/main/src/main/scala/sbt/internal/server/NetworkChannel.scala
+++ b/main/src/main/scala/sbt/internal/server/NetworkChannel.scala
@@ -240,7 +240,13 @@ final class NetworkChannel(val name: String,
     if (isLanguageServerProtocol) {
       event match {
         case entry: StringEvent => logMessage(entry.level, entry.message)
-        case _                  => langRespond(event, execId)
+        case entry: ExecStatusEvent =>
+          entry.exitCode match {
+            case None           => langRespond(event, entry.execId)
+            case Some(0)        => langRespond(event, entry.execId)
+            case Some(exitCode) => langError(entry.execId, exitCode, "")
+          }
+        case _ => langRespond(event, execId)
       }
     } else {
       contentType match {
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 8988c3d057..c91a3bc6f4 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -2,6 +2,6 @@ scalaVersion := "2.12.4"
 scalacOptions ++= Seq("-feature", "-language:postfixOps")
 
 addSbtPlugin("org.scala-sbt"     % "sbt-houserules" % "0.3.5")
-addSbtPlugin("org.scala-sbt"     % "sbt-contraband" % "0.3.2")
+addSbtPlugin("org.scala-sbt"     % "sbt-contraband" % "0.4.0")
 addSbtPlugin("de.heikoseeberger" % "sbt-header"     % "3.0.2")
 addSbtPlugin("com.eed3si9n"      % "sbt-buildinfo"  % "0.8.0")
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/ClientCapabilities.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/ClientCapabilities.scala
index 8e046ede9c..7b6e323135 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/ClientCapabilities.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/ClientCapabilities.scala
@@ -18,7 +18,7 @@ override def hashCode: Int = {
 override def toString: String = {
   "ClientCapabilities()"
 }
-protected[this] def copy(): ClientCapabilities = {
+private[this] def copy(): ClientCapabilities = {
   new ClientCapabilities()
 }
 
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/Diagnostic.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/Diagnostic.scala
index c28bc9b38a..033fae3cfe 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/Diagnostic.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/Diagnostic.scala
@@ -38,7 +38,7 @@ final class Diagnostic private (
   override def toString: String = {
     "Diagnostic(" + range + ", " + severity + ", " + code + ", " + source + ", " + message + ")"
   }
-  protected[this] def copy(range: sbt.internal.langserver.Range = range, severity: Option[Long] = severity, code: Option[String] = code, source: Option[String] = source, message: String = message): Diagnostic = {
+  private[this] def copy(range: sbt.internal.langserver.Range = range, severity: Option[Long] = severity, code: Option[String] = code, source: Option[String] = source, message: String = message): Diagnostic = {
     new Diagnostic(range, severity, code, source, message)
   }
   def withRange(range: sbt.internal.langserver.Range): Diagnostic = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeParams.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeParams.scala
index b96dc94787..7c53991c06 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeParams.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeParams.scala
@@ -25,7 +25,7 @@ final class InitializeParams private (
   override def toString: String = {
     "InitializeParams(" + processId + ", " + rootPath + ", " + rootUri + ", " + initializationOptions + ", " + capabilities + ", " + trace + ")"
   }
-  protected[this] def copy(processId: Option[Long] = processId, rootPath: Option[String] = rootPath, rootUri: Option[String] = rootUri, initializationOptions: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = initializationOptions, capabilities: Option[sbt.internal.langserver.ClientCapabilities] = capabilities, trace: Option[String] = trace): InitializeParams = {
+  private[this] def copy(processId: Option[Long] = processId, rootPath: Option[String] = rootPath, rootUri: Option[String] = rootUri, initializationOptions: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = initializationOptions, capabilities: Option[sbt.internal.langserver.ClientCapabilities] = capabilities, trace: Option[String] = trace): InitializeParams = {
     new InitializeParams(processId, rootPath, rootUri, initializationOptions, capabilities, trace)
   }
   def withProcessId(processId: Option[Long]): InitializeParams = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeResult.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeResult.scala
index 440844dd6b..a7c7978708 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeResult.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/InitializeResult.scala
@@ -20,7 +20,7 @@ final class InitializeResult private (
   override def toString: String = {
     "InitializeResult(" + capabilities + ")"
   }
-  protected[this] def copy(capabilities: sbt.internal.langserver.ServerCapabilities = capabilities): InitializeResult = {
+  private[this] def copy(capabilities: sbt.internal.langserver.ServerCapabilities = capabilities): InitializeResult = {
     new InitializeResult(capabilities)
   }
   def withCapabilities(capabilities: sbt.internal.langserver.ServerCapabilities): InitializeResult = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/Location.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/Location.scala
index 900a426d4e..0fdb660439 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/Location.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/Location.scala
@@ -21,7 +21,7 @@ final class Location private (
   override def toString: String = {
     "Location(" + uri + ", " + range + ")"
   }
-  protected[this] def copy(uri: String = uri, range: sbt.internal.langserver.Range = range): Location = {
+  private[this] def copy(uri: String = uri, range: sbt.internal.langserver.Range = range): Location = {
     new Location(uri, range)
   }
   def withUri(uri: String): Location = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/LogMessageParams.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/LogMessageParams.scala
index a13045afa3..3755c84d0b 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/LogMessageParams.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/LogMessageParams.scala
@@ -22,7 +22,7 @@ final class LogMessageParams private (
   override def toString: String = {
     "LogMessageParams(" + `type` + ", " + message + ")"
   }
-  protected[this] def copy(`type`: Long = `type`, message: String = message): LogMessageParams = {
+  private[this] def copy(`type`: Long = `type`, message: String = message): LogMessageParams = {
     new LogMessageParams(`type`, message)
   }
   def withType(`type`: Long): LogMessageParams = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/Position.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/Position.scala
index f36a278f19..caf248768f 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/Position.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/Position.scala
@@ -26,7 +26,7 @@ final class Position private (
   override def toString: String = {
     "Position(" + line + ", " + character + ")"
   }
-  protected[this] def copy(line: Long = line, character: Long = character): Position = {
+  private[this] def copy(line: Long = line, character: Long = character): Position = {
     new Position(line, character)
   }
   def withLine(line: Long): Position = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/PublishDiagnosticsParams.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/PublishDiagnosticsParams.scala
index 25f7ab7299..3c18fbbabd 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/PublishDiagnosticsParams.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/PublishDiagnosticsParams.scala
@@ -23,7 +23,7 @@ final class PublishDiagnosticsParams private (
   override def toString: String = {
     "PublishDiagnosticsParams(" + uri + ", " + diagnostics + ")"
   }
-  protected[this] def copy(uri: String = uri, diagnostics: Vector[sbt.internal.langserver.Diagnostic] = diagnostics): PublishDiagnosticsParams = {
+  private[this] def copy(uri: String = uri, diagnostics: Vector[sbt.internal.langserver.Diagnostic] = diagnostics): PublishDiagnosticsParams = {
     new PublishDiagnosticsParams(uri, diagnostics)
   }
   def withUri(uri: String): PublishDiagnosticsParams = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/Range.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/Range.scala
index 929bbec5bc..fab914ef54 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/Range.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/Range.scala
@@ -26,7 +26,7 @@ final class Range private (
   override def toString: String = {
     "Range(" + start + ", " + end + ")"
   }
-  protected[this] def copy(start: sbt.internal.langserver.Position = start, end: sbt.internal.langserver.Position = end): Range = {
+  private[this] def copy(start: sbt.internal.langserver.Position = start, end: sbt.internal.langserver.Position = end): Range = {
     new Range(start, end)
   }
   def withStart(start: sbt.internal.langserver.Position): Range = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/SaveOptions.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/SaveOptions.scala
index 347dfca25d..7f66646de1 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/SaveOptions.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/SaveOptions.scala
@@ -20,7 +20,7 @@ final class SaveOptions private (
   override def toString: String = {
     "SaveOptions(" + includeText + ")"
   }
-  protected[this] def copy(includeText: Option[Boolean] = includeText): SaveOptions = {
+  private[this] def copy(includeText: Option[Boolean] = includeText): SaveOptions = {
     new SaveOptions(includeText)
   }
   def withIncludeText(includeText: Option[Boolean]): SaveOptions = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/SbtExecParams.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/SbtExecParams.scala
index d60cc441b4..97f4c5aae4 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/SbtExecParams.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/SbtExecParams.scala
@@ -20,7 +20,7 @@ final class SbtExecParams private (
   override def toString: String = {
     "SbtExecParams(" + commandLine + ")"
   }
-  protected[this] def copy(commandLine: String = commandLine): SbtExecParams = {
+  private[this] def copy(commandLine: String = commandLine): SbtExecParams = {
     new SbtExecParams(commandLine)
   }
   def withCommandLine(commandLine: String): SbtExecParams = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/ServerCapabilities.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/ServerCapabilities.scala
index 8024282140..4aa6c698df 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/ServerCapabilities.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/ServerCapabilities.scala
@@ -23,7 +23,7 @@ final class ServerCapabilities private (
   override def toString: String = {
     "ServerCapabilities(" + textDocumentSync + ", " + hoverProvider + ", " + definitionProvider + ")"
   }
-  protected[this] def copy(textDocumentSync: Option[sbt.internal.langserver.TextDocumentSyncOptions] = textDocumentSync, hoverProvider: Option[Boolean] = hoverProvider, definitionProvider: Option[Boolean] = definitionProvider): ServerCapabilities = {
+  private[this] def copy(textDocumentSync: Option[sbt.internal.langserver.TextDocumentSyncOptions] = textDocumentSync, hoverProvider: Option[Boolean] = hoverProvider, definitionProvider: Option[Boolean] = definitionProvider): ServerCapabilities = {
     new ServerCapabilities(textDocumentSync, hoverProvider, definitionProvider)
   }
   def withTextDocumentSync(textDocumentSync: Option[sbt.internal.langserver.TextDocumentSyncOptions]): ServerCapabilities = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentIdentifier.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentIdentifier.scala
index bb29b3d7fa..dd5a2887fb 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentIdentifier.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentIdentifier.scala
@@ -21,7 +21,7 @@ final class TextDocumentIdentifier private (
   override def toString: String = {
     "TextDocumentIdentifier(" + uri + ")"
   }
-  protected[this] def copy(uri: String = uri): TextDocumentIdentifier = {
+  private[this] def copy(uri: String = uri): TextDocumentIdentifier = {
     new TextDocumentIdentifier(uri)
   }
   def withUri(uri: String): TextDocumentIdentifier = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentPositionParams.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentPositionParams.scala
index 5d7d3edd8a..10717f0fc8 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentPositionParams.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentPositionParams.scala
@@ -23,7 +23,7 @@ final class TextDocumentPositionParams private (
   override def toString: String = {
     "TextDocumentPositionParams(" + textDocument + ", " + position + ")"
   }
-  protected[this] def copy(textDocument: sbt.internal.langserver.TextDocumentIdentifier = textDocument, position: sbt.internal.langserver.Position = position): TextDocumentPositionParams = {
+  private[this] def copy(textDocument: sbt.internal.langserver.TextDocumentIdentifier = textDocument, position: sbt.internal.langserver.Position = position): TextDocumentPositionParams = {
     new TextDocumentPositionParams(textDocument, position)
   }
   def withTextDocument(textDocument: sbt.internal.langserver.TextDocumentIdentifier): TextDocumentPositionParams = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentSyncOptions.scala b/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentSyncOptions.scala
index d94f50428b..4822a9aecd 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentSyncOptions.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/langserver/TextDocumentSyncOptions.scala
@@ -23,7 +23,7 @@ final class TextDocumentSyncOptions private (
   override def toString: String = {
     "TextDocumentSyncOptions(" + openClose + ", " + change + ", " + willSave + ", " + willSaveWaitUntil + ", " + save + ")"
   }
-  protected[this] def copy(openClose: Option[Boolean] = openClose, change: Option[Long] = change, willSave: Option[Boolean] = willSave, willSaveWaitUntil: Option[Boolean] = willSaveWaitUntil, save: Option[sbt.internal.langserver.SaveOptions] = save): TextDocumentSyncOptions = {
+  private[this] def copy(openClose: Option[Boolean] = openClose, change: Option[Long] = change, willSave: Option[Boolean] = willSave, willSaveWaitUntil: Option[Boolean] = willSaveWaitUntil, save: Option[sbt.internal.langserver.SaveOptions] = save): TextDocumentSyncOptions = {
     new TextDocumentSyncOptions(openClose, change, willSave, willSaveWaitUntil, save)
   }
   def withOpenClose(openClose: Option[Boolean]): TextDocumentSyncOptions = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/InitializeOption.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/InitializeOption.scala
index eeda8fa2c7..ff2f27c9cf 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/InitializeOption.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/InitializeOption.scala
@@ -19,7 +19,7 @@ final class InitializeOption private (
   override def toString: String = {
     "InitializeOption(" + token + ")"
   }
-  protected[this] def copy(token: Option[String] = token): InitializeOption = {
+  private[this] def copy(token: Option[String] = token): InitializeOption = {
     new InitializeOption(token)
   }
   def withToken(token: Option[String]): InitializeOption = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcNotificationMessage.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcNotificationMessage.scala
index aa55a36397..b3edb6b9dd 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcNotificationMessage.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcNotificationMessage.scala
@@ -23,7 +23,7 @@ final class JsonRpcNotificationMessage private (
   override def toString: String = {
     s"""JsonRpcNotificationMessage($jsonrpc, $method, ${sbt.protocol.Serialization.compactPrintJsonOpt(params)})"""
   }
-  protected[this] def copy(jsonrpc: String = jsonrpc, method: String = method, params: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = params): JsonRpcNotificationMessage = {
+  private[this] def copy(jsonrpc: String = jsonrpc, method: String = method, params: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = params): JsonRpcNotificationMessage = {
     new JsonRpcNotificationMessage(jsonrpc, method, params)
   }
   def withJsonrpc(jsonrpc: String): JsonRpcNotificationMessage = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcRequestMessage.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcRequestMessage.scala
index f5943e1f7d..d406113793 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcRequestMessage.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcRequestMessage.scala
@@ -25,7 +25,7 @@ final class JsonRpcRequestMessage private (
   override def toString: String = {
     s"""JsonRpcRequestMessage($jsonrpc, $id, $method, ${sbt.protocol.Serialization.compactPrintJsonOpt(params)}})"""
   }
-  protected[this] def copy(jsonrpc: String = jsonrpc, id: String = id, method: String = method, params: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = params): JsonRpcRequestMessage = {
+  private[this] def copy(jsonrpc: String = jsonrpc, id: String = id, method: String = method, params: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = params): JsonRpcRequestMessage = {
     new JsonRpcRequestMessage(jsonrpc, id, method, params)
   }
   def withJsonrpc(jsonrpc: String): JsonRpcRequestMessage = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseError.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseError.scala
index 9ece998526..68541873ea 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseError.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseError.scala
@@ -27,7 +27,7 @@ final class JsonRpcResponseError private (
   override def toString: String = {
     s"""JsonRpcResponseError($code, $message, ${sbt.protocol.Serialization.compactPrintJsonOpt(data)})"""
   }
-  protected[this] def copy(code: Long = code, message: String = message, data: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = data): JsonRpcResponseError = {
+  private[this] def copy(code: Long = code, message: String = message, data: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = data): JsonRpcResponseError = {
     new JsonRpcResponseError(code, message, data)
   }
   def withCode(code: Long): JsonRpcResponseError = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseMessage.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseMessage.scala
index dd01ae0d30..b2d1596b44 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseMessage.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/JsonRpcResponseMessage.scala
@@ -28,7 +28,7 @@ final class JsonRpcResponseMessage private (
   override def toString: String = {
     s"""JsonRpcResponseMessage($jsonrpc, $id, ${sbt.protocol.Serialization.compactPrintJsonOpt(result)}, $error)"""
   }
-  protected[this] def copy(jsonrpc: String = jsonrpc, id: Option[String] = id, result: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = result, error: Option[sbt.internal.protocol.JsonRpcResponseError] = error): JsonRpcResponseMessage = {
+  private[this] def copy(jsonrpc: String = jsonrpc, id: Option[String] = id, result: Option[sjsonnew.shaded.scalajson.ast.unsafe.JValue] = result, error: Option[sbt.internal.protocol.JsonRpcResponseError] = error): JsonRpcResponseMessage = {
     new JsonRpcResponseMessage(jsonrpc, id, result, error)
   }
   def withJsonrpc(jsonrpc: String): JsonRpcResponseMessage = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/PortFile.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/PortFile.scala
index 218aefdfb7..8354bc5b4f 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/PortFile.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/PortFile.scala
@@ -26,7 +26,7 @@ final class PortFile private (
   override def toString: String = {
     "PortFile(" + uri + ", " + tokenfilePath + ", " + tokenfileUri + ")"
   }
-  protected[this] def copy(uri: String = uri, tokenfilePath: Option[String] = tokenfilePath, tokenfileUri: Option[String] = tokenfileUri): PortFile = {
+  private[this] def copy(uri: String = uri, tokenfilePath: Option[String] = tokenfilePath, tokenfileUri: Option[String] = tokenfileUri): PortFile = {
     new PortFile(uri, tokenfilePath, tokenfileUri)
   }
   def withUri(uri: String): PortFile = {
diff --git a/protocol/src/main/contraband-scala/sbt/internal/protocol/TokenFile.scala b/protocol/src/main/contraband-scala/sbt/internal/protocol/TokenFile.scala
index e2019147e9..88c218a7d6 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/protocol/TokenFile.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/protocol/TokenFile.scala
@@ -20,7 +20,7 @@ final class TokenFile private (
   override def toString: String = {
     "TokenFile(" + uri + ", " + token + ")"
   }
-  protected[this] def copy(uri: String = uri, token: String = token): TokenFile = {
+  private[this] def copy(uri: String = uri, token: String = token): TokenFile = {
     new TokenFile(uri, token)
   }
   def withUri(uri: String): TokenFile = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/ChannelAcceptedEvent.scala b/protocol/src/main/contraband-scala/sbt/protocol/ChannelAcceptedEvent.scala
index 8bb6dffcb5..65191d0290 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/ChannelAcceptedEvent.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/ChannelAcceptedEvent.scala
@@ -19,7 +19,7 @@ final class ChannelAcceptedEvent private (
   override def toString: String = {
     "ChannelAcceptedEvent(" + channelName + ")"
   }
-  protected[this] def copy(channelName: String = channelName): ChannelAcceptedEvent = {
+  private[this] def copy(channelName: String = channelName): ChannelAcceptedEvent = {
     new ChannelAcceptedEvent(channelName)
   }
   def withChannelName(channelName: String): ChannelAcceptedEvent = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/ExecCommand.scala b/protocol/src/main/contraband-scala/sbt/protocol/ExecCommand.scala
index df022897d4..142d449757 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/ExecCommand.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/ExecCommand.scala
@@ -21,7 +21,7 @@ final class ExecCommand private (
   override def toString: String = {
     "ExecCommand(" + commandLine + ", " + execId + ")"
   }
-  protected[this] def copy(commandLine: String = commandLine, execId: Option[String] = execId): ExecCommand = {
+  private[this] def copy(commandLine: String = commandLine, execId: Option[String] = execId): ExecCommand = {
     new ExecCommand(commandLine, execId)
   }
   def withCommandLine(commandLine: String): ExecCommand = {
@@ -36,7 +36,7 @@ final class ExecCommand private (
 }
 object ExecCommand {
   
-  def apply(commandLine: String): ExecCommand = new ExecCommand(commandLine, None)
+  def apply(commandLine: String): ExecCommand = new ExecCommand(commandLine)
   def apply(commandLine: String, execId: Option[String]): ExecCommand = new ExecCommand(commandLine, execId)
   def apply(commandLine: String, execId: String): ExecCommand = new ExecCommand(commandLine, Option(execId))
 }
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/ExecStatusEvent.scala b/protocol/src/main/contraband-scala/sbt/protocol/ExecStatusEvent.scala
index 5ce5793978..3f42e03161 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/ExecStatusEvent.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/ExecStatusEvent.scala
@@ -9,22 +9,23 @@ final class ExecStatusEvent private (
   val status: String,
   val channelName: Option[String],
   val execId: Option[String],
-  val commandQueue: Vector[String]) extends sbt.protocol.EventMessage() with Serializable {
-  
+  val commandQueue: Vector[String],
+  val exitCode: Option[Long]) extends sbt.protocol.EventMessage() with Serializable {
   
+  private def this(status: String, channelName: Option[String], execId: Option[String], commandQueue: Vector[String]) = this(status, channelName, execId, commandQueue, None)
   
   override def equals(o: Any): Boolean = o match {
-    case x: ExecStatusEvent => (this.status == x.status) && (this.channelName == x.channelName) && (this.execId == x.execId) && (this.commandQueue == x.commandQueue)
+    case x: ExecStatusEvent => (this.status == x.status) && (this.channelName == x.channelName) && (this.execId == x.execId) && (this.commandQueue == x.commandQueue) && (this.exitCode == x.exitCode)
     case _ => false
   }
   override def hashCode: Int = {
-    37 * (37 * (37 * (37 * (37 * (17 + "sbt.protocol.ExecStatusEvent".##) + status.##) + channelName.##) + execId.##) + commandQueue.##)
+    37 * (37 * (37 * (37 * (37 * (37 * (17 + "sbt.protocol.ExecStatusEvent".##) + status.##) + channelName.##) + execId.##) + commandQueue.##) + exitCode.##)
   }
   override def toString: String = {
-    "ExecStatusEvent(" + status + ", " + channelName + ", " + execId + ", " + commandQueue + ")"
+    "ExecStatusEvent(" + status + ", " + channelName + ", " + execId + ", " + commandQueue + ", " + exitCode + ")"
   }
-  protected[this] def copy(status: String = status, channelName: Option[String] = channelName, execId: Option[String] = execId, commandQueue: Vector[String] = commandQueue): ExecStatusEvent = {
-    new ExecStatusEvent(status, channelName, execId, commandQueue)
+  private[this] def copy(status: String = status, channelName: Option[String] = channelName, execId: Option[String] = execId, commandQueue: Vector[String] = commandQueue, exitCode: Option[Long] = exitCode): ExecStatusEvent = {
+    new ExecStatusEvent(status, channelName, execId, commandQueue, exitCode)
   }
   def withStatus(status: String): ExecStatusEvent = {
     copy(status = status)
@@ -44,9 +45,17 @@ final class ExecStatusEvent private (
   def withCommandQueue(commandQueue: Vector[String]): ExecStatusEvent = {
     copy(commandQueue = commandQueue)
   }
+  def withExitCode(exitCode: Option[Long]): ExecStatusEvent = {
+    copy(exitCode = exitCode)
+  }
+  def withExitCode(exitCode: Long): ExecStatusEvent = {
+    copy(exitCode = Option(exitCode))
+  }
 }
 object ExecStatusEvent {
   
   def apply(status: String, channelName: Option[String], execId: Option[String], commandQueue: Vector[String]): ExecStatusEvent = new ExecStatusEvent(status, channelName, execId, commandQueue)
   def apply(status: String, channelName: String, execId: String, commandQueue: Vector[String]): ExecStatusEvent = new ExecStatusEvent(status, Option(channelName), Option(execId), commandQueue)
+  def apply(status: String, channelName: Option[String], execId: Option[String], commandQueue: Vector[String], exitCode: Option[Long]): ExecStatusEvent = new ExecStatusEvent(status, channelName, execId, commandQueue, exitCode)
+  def apply(status: String, channelName: String, execId: String, commandQueue: Vector[String], exitCode: Long): ExecStatusEvent = new ExecStatusEvent(status, Option(channelName), Option(execId), commandQueue, Option(exitCode))
 }
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/ExecutionEvent.scala b/protocol/src/main/contraband-scala/sbt/protocol/ExecutionEvent.scala
index f47c3b7419..fdcac99755 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/ExecutionEvent.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/ExecutionEvent.scala
@@ -21,7 +21,7 @@ final class ExecutionEvent private (
   override def toString: String = {
     "ExecutionEvent(" + success + ", " + commandLine + ")"
   }
-  protected[this] def copy(success: String = success, commandLine: String = commandLine): ExecutionEvent = {
+  private[this] def copy(success: String = success, commandLine: String = commandLine): ExecutionEvent = {
     new ExecutionEvent(success, commandLine)
   }
   def withSuccess(success: String): ExecutionEvent = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/InitCommand.scala b/protocol/src/main/contraband-scala/sbt/protocol/InitCommand.scala
index e45b25c84a..b454552d5b 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/InitCommand.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/InitCommand.scala
@@ -20,7 +20,7 @@ final class InitCommand private (
   override def toString: String = {
     "InitCommand(" + token + ", " + execId + ")"
   }
-  protected[this] def copy(token: Option[String] = token, execId: Option[String] = execId): InitCommand = {
+  private[this] def copy(token: Option[String] = token, execId: Option[String] = execId): InitCommand = {
     new InitCommand(token, execId)
   }
   def withToken(token: Option[String]): InitCommand = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/LogEvent.scala b/protocol/src/main/contraband-scala/sbt/protocol/LogEvent.scala
index 6946352524..27acd0656a 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/LogEvent.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/LogEvent.scala
@@ -21,7 +21,7 @@ final class LogEvent private (
   override def toString: String = {
     "LogEvent(" + level + ", " + message + ")"
   }
-  protected[this] def copy(level: String = level, message: String = message): LogEvent = {
+  private[this] def copy(level: String = level, message: String = message): LogEvent = {
     new LogEvent(level, message)
   }
   def withLevel(level: String): LogEvent = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/SettingQuery.scala b/protocol/src/main/contraband-scala/sbt/protocol/SettingQuery.scala
index a00fd05d6c..2846234ef3 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/SettingQuery.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/SettingQuery.scala
@@ -19,7 +19,7 @@ final class SettingQuery private (
   override def toString: String = {
     "SettingQuery(" + setting + ")"
   }
-  protected[this] def copy(setting: String = setting): SettingQuery = {
+  private[this] def copy(setting: String = setting): SettingQuery = {
     new SettingQuery(setting)
   }
   def withSetting(setting: String): SettingQuery = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/SettingQueryFailure.scala b/protocol/src/main/contraband-scala/sbt/protocol/SettingQueryFailure.scala
index 9c5305b96c..16102225d2 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/SettingQueryFailure.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/SettingQueryFailure.scala
@@ -19,7 +19,7 @@ final class SettingQueryFailure private (
   override def toString: String = {
     "SettingQueryFailure(" + message + ")"
   }
-  protected[this] def copy(message: String = message): SettingQueryFailure = {
+  private[this] def copy(message: String = message): SettingQueryFailure = {
     new SettingQueryFailure(message)
   }
   def withMessage(message: String): SettingQueryFailure = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/SettingQuerySuccess.scala b/protocol/src/main/contraband-scala/sbt/protocol/SettingQuerySuccess.scala
index be6af35fca..ab9c6d2ee1 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/SettingQuerySuccess.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/SettingQuerySuccess.scala
@@ -20,7 +20,7 @@ final class SettingQuerySuccess private (
   override def toString: String = {
     "SettingQuerySuccess(" + value + ", " + contentType + ")"
   }
-  protected[this] def copy(value: sjsonnew.shaded.scalajson.ast.unsafe.JValue = value, contentType: String = contentType): SettingQuerySuccess = {
+  private[this] def copy(value: sjsonnew.shaded.scalajson.ast.unsafe.JValue = value, contentType: String = contentType): SettingQuerySuccess = {
     new SettingQuerySuccess(value, contentType)
   }
   def withValue(value: sjsonnew.shaded.scalajson.ast.unsafe.JValue): SettingQuerySuccess = {
diff --git a/protocol/src/main/contraband-scala/sbt/protocol/codec/ExecStatusEventFormats.scala b/protocol/src/main/contraband-scala/sbt/protocol/codec/ExecStatusEventFormats.scala
index 7b906fb1a0..0f9c1f10ea 100644
--- a/protocol/src/main/contraband-scala/sbt/protocol/codec/ExecStatusEventFormats.scala
+++ b/protocol/src/main/contraband-scala/sbt/protocol/codec/ExecStatusEventFormats.scala
@@ -15,8 +15,9 @@ implicit lazy val ExecStatusEventFormat: JsonFormat[sbt.protocol.ExecStatusEvent
       val channelName = unbuilder.readField[Option[String]]("channelName")
       val execId = unbuilder.readField[Option[String]]("execId")
       val commandQueue = unbuilder.readField[Vector[String]]("commandQueue")
+      val exitCode = unbuilder.readField[Option[Long]]("exitCode")
       unbuilder.endObject()
-      sbt.protocol.ExecStatusEvent(status, channelName, execId, commandQueue)
+      sbt.protocol.ExecStatusEvent(status, channelName, execId, commandQueue, exitCode)
       case None =>
       deserializationError("Expected JsObject but found None")
     }
@@ -27,6 +28,7 @@ implicit lazy val ExecStatusEventFormat: JsonFormat[sbt.protocol.ExecStatusEvent
     builder.addField("channelName", obj.channelName)
     builder.addField("execId", obj.execId)
     builder.addField("commandQueue", obj.commandQueue)
+    builder.addField("exitCode", obj.exitCode)
     builder.endObject()
   }
 }
diff --git a/protocol/src/main/contraband/server.contra b/protocol/src/main/contraband/server.contra
index 2976be2297..63c7b816d6 100644
--- a/protocol/src/main/contraband/server.contra
+++ b/protocol/src/main/contraband/server.contra
@@ -43,6 +43,7 @@ type ExecStatusEvent implements EventMessage {
   channelName: String
   execId: String
   commandQueue: [String]
+  exitCode: Long @since("1.1.2")
 }
 
 interface SettingQueryResponse implements EventMessage {}
diff --git a/protocol/src/main/scala/sbt/internal/langserver/ErrorCodes.scala b/protocol/src/main/scala/sbt/internal/langserver/ErrorCodes.scala
index 952cf78961..4b67ee90a7 100644
--- a/protocol/src/main/scala/sbt/internal/langserver/ErrorCodes.scala
+++ b/protocol/src/main/scala/sbt/internal/langserver/ErrorCodes.scala
@@ -9,18 +9,40 @@ package sbt
 package internal
 package langserver
 
+/** Holds the error codes for the LSP implementation here. */
 object ErrorCodes {
-  // Defined by JSON RPC
-  val ParseError = -32700L
-  val InvalidRequest = -32600L
-  val MethodNotFound = -32601L
-  val InvalidParams = -32602L
-  val InternalError = -32603L
-  val serverErrorStart = -32099L
-  val serverErrorEnd = -32000L
-  val ServerNotInitialized = -32002L
-  val UnknownErrorCode = -32001L
-
-  // Defined by the protocol.
-  val RequestCancelled = -32800L
+  // this is essentially a lookup table encoded in Scala,
+  // so heavy usage of vertical alignment is beneficial
+  // format: off
+
+  // Defined by the JSON-RPC 2.0 Specification
+  // http://www.jsonrpc.org/specification#error_object
+  //
+  // The error codes from and including -32768 to -32000 are reserved for pre-defined errors.
+  // Any code within this range, but not defined explicitly below is reserved for future use.
+  //
+  // The error codes are nearly the same as those suggested for XML-RPC at the following url:
+  // http://xmlrpc-epi.sourceforge.net/specs/rfc.fault_codes.php
+  //
+  val ParseError     = -32700L       // Invalid JSON was received by the server.
+                                     // An error occurred on the server while parsing the JSON text.
+  val InvalidRequest = -32600L       // The JSON sent is not a valid Request object.
+  val MethodNotFound = -32601L       // The method does not exist / is not available.
+  val InvalidParams  = -32602L       // Invalid method parameter(s).
+  val InternalError  = -32603L       // Internal JSON-RPC error.
+
+
+  // The range -32000 to -32099 are reserved for implementation-defined server-errors.
+  val serverErrorStart = -32099L     // from LSP's spec code snippet
+  val serverErrorEnd   = -32000L     // from LSP's spec code snippet
+
+  val UnknownServerError   = -32001L // Defined by LSP
+  val ServerNotInitialized = -32002L // Defined by LSP
+
+
+  // The remainder of the space is available for application defined errors.
+  val RequestCancelled = -32800L     // Defined by LSP
+  val UnknownError     = -33000L     // A generic error, unknown if the user or server is at fault.
+
+  // format: on
 }
diff --git a/run/src/main/contraband-scala/sbt/ForkOptions.scala b/run/src/main/contraband-scala/sbt/ForkOptions.scala
index ece8ca699d..b8f30ab157 100644
--- a/run/src/main/contraband-scala/sbt/ForkOptions.scala
+++ b/run/src/main/contraband-scala/sbt/ForkOptions.scala
@@ -43,7 +43,7 @@ final class ForkOptions private (
   override def toString: String = {
     "ForkOptions(" + javaHome + ", " + outputStrategy + ", " + bootJars + ", " + workingDirectory + ", " + runJVMOptions + ", " + connectInput + ", " + envVars + ")"
   }
-  protected[this] def copy(javaHome: Option[java.io.File] = javaHome, outputStrategy: Option[sbt.OutputStrategy] = outputStrategy, bootJars: Vector[java.io.File] = bootJars, workingDirectory: Option[java.io.File] = workingDirectory, runJVMOptions: Vector[String] = runJVMOptions, connectInput: Boolean = connectInput, envVars: scala.collection.immutable.Map[String, String] = envVars): ForkOptions = {
+  private[this] def copy(javaHome: Option[java.io.File] = javaHome, outputStrategy: Option[sbt.OutputStrategy] = outputStrategy, bootJars: Vector[java.io.File] = bootJars, workingDirectory: Option[java.io.File] = workingDirectory, runJVMOptions: Vector[String] = runJVMOptions, connectInput: Boolean = connectInput, envVars: scala.collection.immutable.Map[String, String] = envVars): ForkOptions = {
     new ForkOptions(javaHome, outputStrategy, bootJars, workingDirectory, runJVMOptions, connectInput, envVars)
   }
   def withJavaHome(javaHome: Option[java.io.File]): ForkOptions = {
@@ -79,7 +79,7 @@ final class ForkOptions private (
 }
 object ForkOptions {
   
-  def apply(): ForkOptions = new ForkOptions(None, None, Vector(), None, Vector(), false, Map())
+  def apply(): ForkOptions = new ForkOptions()
   def apply(javaHome: Option[java.io.File], outputStrategy: Option[sbt.OutputStrategy], bootJars: Vector[java.io.File], workingDirectory: Option[java.io.File], runJVMOptions: Vector[String], connectInput: Boolean, envVars: scala.collection.immutable.Map[String, String]): ForkOptions = new ForkOptions(javaHome, outputStrategy, bootJars, workingDirectory, runJVMOptions, connectInput, envVars)
   def apply(javaHome: java.io.File, outputStrategy: sbt.OutputStrategy, bootJars: Vector[java.io.File], workingDirectory: java.io.File, runJVMOptions: Vector[String], connectInput: Boolean, envVars: scala.collection.immutable.Map[String, String]): ForkOptions = new ForkOptions(Option(javaHome), Option(outputStrategy), bootJars, Option(workingDirectory), runJVMOptions, connectInput, envVars)
 }
diff --git a/run/src/main/scala/sbt/OutputStrategy.scala b/run/src/main/scala/sbt/OutputStrategy.scala
index be1031e306..1f6d819cfa 100644
--- a/run/src/main/scala/sbt/OutputStrategy.scala
+++ b/run/src/main/scala/sbt/OutputStrategy.scala
@@ -37,7 +37,7 @@ object OutputStrategy {
     override def toString: String = {
       "BufferedOutput(" + logger + ")"
     }
-    protected[this] def copy(logger: Logger = logger): BufferedOutput = {
+    private[this] def copy(logger: Logger = logger): BufferedOutput = {
       new BufferedOutput(logger)
     }
     def withLogger(logger: Logger): BufferedOutput = {
@@ -63,7 +63,7 @@ object OutputStrategy {
     override def toString: String = {
       "LoggedOutput(" + logger + ")"
     }
-    protected[this] def copy(logger: Logger = logger): LoggedOutput = {
+    private[this] def copy(logger: Logger = logger): LoggedOutput = {
       new LoggedOutput(logger)
     }
     def withLogger(logger: Logger): LoggedOutput = {
@@ -91,7 +91,7 @@ object OutputStrategy {
     override def toString: String = {
       "CustomOutput(" + output + ")"
     }
-    protected[this] def copy(output: OutputStream = output): CustomOutput = {
+    private[this] def copy(output: OutputStream = output): CustomOutput = {
       new CustomOutput(output)
     }
     def withOutput(output: OutputStream): CustomOutput = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupErrorEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupErrorEvent.scala
index afeeef6ac5..b6cf91afa0 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupErrorEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupErrorEvent.scala
@@ -21,7 +21,7 @@ final class EndTestGroupErrorEvent private (
   override def toString: String = {
     "EndTestGroupErrorEvent(" + name + ", " + error + ")"
   }
-  protected[this] def copy(name: String = name, error: String = error): EndTestGroupErrorEvent = {
+  private[this] def copy(name: String = name, error: String = error): EndTestGroupErrorEvent = {
     new EndTestGroupErrorEvent(name, error)
   }
   def withName(name: String): EndTestGroupErrorEvent = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupEvent.scala
index db3893a84e..802a64843b 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/EndTestGroupEvent.scala
@@ -21,7 +21,7 @@ final class EndTestGroupEvent private (
   override def toString: String = {
     "EndTestGroupEvent(" + name + ", " + result + ")"
   }
-  protected[this] def copy(name: String = name, result: sbt.protocol.testing.TestResult = result): EndTestGroupEvent = {
+  private[this] def copy(name: String = name, result: sbt.protocol.testing.TestResult = result): EndTestGroupEvent = {
     new EndTestGroupEvent(name, result)
   }
   def withName(name: String): EndTestGroupEvent = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/StartTestGroupEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/StartTestGroupEvent.scala
index 156c4ba575..ed1ca2f9a4 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/StartTestGroupEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/StartTestGroupEvent.scala
@@ -20,7 +20,7 @@ final class StartTestGroupEvent private (
   override def toString: String = {
     "StartTestGroupEvent(" + name + ")"
   }
-  protected[this] def copy(name: String = name): StartTestGroupEvent = {
+  private[this] def copy(name: String = name): StartTestGroupEvent = {
     new StartTestGroupEvent(name)
   }
   def withName(name: String): StartTestGroupEvent = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/TestCompleteEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/TestCompleteEvent.scala
index e441880849..c3d0fb4f61 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/TestCompleteEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/TestCompleteEvent.scala
@@ -20,7 +20,7 @@ final class TestCompleteEvent private (
   override def toString: String = {
     "TestCompleteEvent(" + result + ")"
   }
-  protected[this] def copy(result: sbt.protocol.testing.TestResult = result): TestCompleteEvent = {
+  private[this] def copy(result: sbt.protocol.testing.TestResult = result): TestCompleteEvent = {
     new TestCompleteEvent(result)
   }
   def withResult(result: sbt.protocol.testing.TestResult): TestCompleteEvent = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/TestInitEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/TestInitEvent.scala
index b6178c40fe..cf96623d98 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/TestInitEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/TestInitEvent.scala
@@ -19,7 +19,7 @@ override def hashCode: Int = {
 override def toString: String = {
   "TestInitEvent()"
 }
-protected[this] def copy(): TestInitEvent = {
+private[this] def copy(): TestInitEvent = {
   new TestInitEvent()
 }
 
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemDetail.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemDetail.scala
index 50762dcb52..904cdc258e 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemDetail.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemDetail.scala
@@ -31,7 +31,7 @@ final class TestItemDetail private (
   override def toString: String = {
     "TestItemDetail(" + fullyQualifiedName + ", " + status + ", " + duration + ")"
   }
-  protected[this] def copy(fullyQualifiedName: String = fullyQualifiedName, status: sbt.testing.Status = status, duration: Option[Long] = duration): TestItemDetail = {
+  private[this] def copy(fullyQualifiedName: String = fullyQualifiedName, status: sbt.testing.Status = status, duration: Option[Long] = duration): TestItemDetail = {
     new TestItemDetail(fullyQualifiedName, status, duration)
   }
   def withFullyQualifiedName(fullyQualifiedName: String): TestItemDetail = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemEvent.scala
index d7f343f7bf..6910d1b16e 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/TestItemEvent.scala
@@ -21,7 +21,7 @@ final class TestItemEvent private (
   override def toString: String = {
     "TestItemEvent(" + result + ", " + detail + ")"
   }
-  protected[this] def copy(result: Option[sbt.protocol.testing.TestResult] = result, detail: Vector[sbt.protocol.testing.TestItemDetail] = detail): TestItemEvent = {
+  private[this] def copy(result: Option[sbt.protocol.testing.TestResult] = result, detail: Vector[sbt.protocol.testing.TestItemDetail] = detail): TestItemEvent = {
     new TestItemEvent(result, detail)
   }
   def withResult(result: Option[sbt.protocol.testing.TestResult]): TestItemEvent = {
diff --git a/testing/src/main/contraband-scala/sbt/protocol/testing/TestStringEvent.scala b/testing/src/main/contraband-scala/sbt/protocol/testing/TestStringEvent.scala
index 618faf180b..6b3f5d973d 100644
--- a/testing/src/main/contraband-scala/sbt/protocol/testing/TestStringEvent.scala
+++ b/testing/src/main/contraband-scala/sbt/protocol/testing/TestStringEvent.scala
@@ -19,7 +19,7 @@ final class TestStringEvent private (
   override def toString: String = {
     value
   }
-  protected[this] def copy(value: String = value): TestStringEvent = {
+  private[this] def copy(value: String = value): TestStringEvent = {
     new TestStringEvent(value)
   }
   def withValue(value: String): TestStringEvent = {