Use java command in BspConnectionDetails

main-command/src/main/scala/sbt/internal/server/Server.scala

@@ -10,6 +10,7 @@ package internal
 package server
 
 import java.io.{ File, IOException }
+import java.lang.management.ManagementFactory
 import java.net.{ InetAddress, ServerSocket, Socket, SocketTimeoutException }
 import java.util.concurrent.atomic.AtomicBoolean
 import java.nio.file.attribute.{ AclEntry, AclEntryPermission, AclEntryType, UserPrincipal }
@@ -28,6 +29,7 @@ import sbt.internal.util.ErrorHandling
 import sbt.internal.util.Util.isWindows
 import org.scalasbt.ipcsocket._
 import sbt.internal.bsp.BuildServerConnection
+import xsbti.AppConfiguration
 
 private[sbt] sealed trait ServerInstance {
   def shutdown(): Unit
@@ -199,7 +201,9 @@ private[sbt] object Server {
 
       private[this] def writeBspConnectionDetails(): Unit = {
         import bsp.codec.JsonProtocol._
-        val details = BuildServerConnection.details(sbtVersion)
+        val sbtVersion = appConfiguration.provider.id.version
+        val launcherJar = ManagementFactory.getRuntimeMXBean.getClassPath
+        val details = BuildServerConnection.details(sbtVersion, launcherJar)
         val json = Converter.toJson(details).get
         IO.write(bspConnectionFile, CompactPrinter(json), append = false)
       }
@@ -223,7 +227,7 @@ private[sbt] case class ServerConnection(
     socketfile: File,
     pipeName: String,
     bspConnectionFile: File,
-    sbtVersion: String
+    appConfiguration: AppConfiguration
 ) {
   def shortName: String = {
     connectionType match {

main/src/main/scala/sbt/internal/CommandExchange.scala

@@ -118,7 +118,6 @@ private[sbt] final class CommandExchange {
   private[sbt] def runServer(s: State): State = {
     lazy val port = s.get(serverPort).getOrElse(5001)
     lazy val host = s.get(serverHost).getOrElse("127.0.0.1")
-    lazy val sbtVersion = s.configuration.provider.id.version
     lazy val auth: Set[ServerAuthentication] =
       s.get(serverAuthentication).getOrElse(Set(ServerAuthentication.Token))
     lazy val connectionType = s.get(serverConnectionType).getOrElse(ConnectionType.Tcp)
@@ -159,7 +158,7 @@ private[sbt] final class CommandExchange {
         socketfile,
         pipeName,
         bspConnectionFile,
-        sbtVersion
+        s.configuration
       )
       val serverInstance = Server.start(connection, onIncomingSocket, s.log)
       // don't throw exception when it times out

protocol/src/main/scala/sbt/internal/bsp/BuildServerConnection.scala

@@ -11,8 +11,9 @@ object BuildServerConnection {
   final val name = "sbt"
   final val bspVersion = "2.0.0-M5"
   final val languages = Vector("scala")
-  final val argv = Vector("sbt", "-bsp")
-  def details(sbtVersion: String): BspConnectionDetails = {
+
+  def details(sbtVersion: String, launcherJar: String): BspConnectionDetails = {
+    val argv = Vector("java", "-Xms100m", "-Xmx100m", "-jar", launcherJar, "-bsp")
     BspConnectionDetails(name, sbtVersion, bspVersion, languages, argv)
   }
 }