diff --git a/internal/util-complete/src/main/scala/sbt/internal/util/LineReader.scala b/internal/util-complete/src/main/scala/sbt/internal/util/LineReader.scala
index 4b0235572..a963582f4 100644
--- a/internal/util-complete/src/main/scala/sbt/internal/util/LineReader.scala
+++ b/internal/util-complete/src/main/scala/sbt/internal/util/LineReader.scala
@@ -74,13 +74,13 @@ object LineReader {
       parser: Parser[_],
       terminal: Terminal,
   ): LineReader = {
-    val term = JLine3(terminal)
     // We may want to consider insourcing LineReader.java from jline. We don't otherwise
     // directly need jline3 for sbt.
-    val reader = LineReaderBuilder.builder().terminal(term).completer(completer(parser)).build()
-    historyPath.foreach(f => reader.setVariable(JLineReader.HISTORY_FILE, f))
     new LineReader {
       override def readLine(prompt: String, mask: Option[Char]): Option[String] = {
+        val term = JLine3(terminal)
+        val reader = LineReaderBuilder.builder().terminal(term).completer(completer(parser)).build()
+        historyPath.foreach(f => reader.setVariable(JLineReader.HISTORY_FILE, f))
         try terminal.withRawInput {
           Option(mask.map(reader.readLine(prompt, _)).getOrElse(reader.readLine(prompt)))
         } catch {
diff --git a/main-command/src/main/scala/sbt/internal/ui/UITask.scala b/main-command/src/main/scala/sbt/internal/ui/UITask.scala
index 8fd4d4177..f47def3a6 100644
--- a/main-command/src/main/scala/sbt/internal/ui/UITask.scala
+++ b/main-command/src/main/scala/sbt/internal/ui/UITask.scala
@@ -59,7 +59,7 @@ private[sbt] object UITask {
       def readLine(): Either[String, String] =
         try {
           val clear = terminal.ansi(ClearPromptLine, "")
-          @tailrec def impl(): Either[String, String] = {
+          val res = {
             val thread = Thread.currentThread
             if (thread.isInterrupted || closed.get) throw interrupted
             val reader = LineReader.createReader(history(state), parser, terminal)
@@ -76,16 +76,17 @@ private[sbt] object UITask {
               case None => Left(TerminateAction)
               case Some(s: String) =>
                 s.trim() match {
-                  case ""                                                => impl()
+                  // We need to put the empty string on the fast track queue so that we can
+                  // reprompt the user if another command is running on the server.
+                  case ""                                                => Left("")
                   case cmd @ (`Shutdown` | `TerminateAction` | `Cancel`) => Left(cmd)
                   case cmd                                               => Right(cmd)
                 }
             }
           }
-          val res = impl()
           terminal.setPrompt(Prompt.Pending)
           res
-        } catch { case e: InterruptedException => Right("") }
+        } catch { case e: InterruptedException => Left("") }
       override def close(): Unit = closed.set(true)
     }
   }
diff --git a/main/src/main/scala/sbt/internal/CommandExchange.scala b/main/src/main/scala/sbt/internal/CommandExchange.scala
index 505c913c2..b2d077a4c 100644
--- a/main/src/main/scala/sbt/internal/CommandExchange.scala
+++ b/main/src/main/scala/sbt/internal/CommandExchange.scala
@@ -446,7 +446,7 @@ private[sbt] final class CommandExchange {
           case null =>
           case mt: FastTrackTask =>
             mt.task match {
-              case `attach` => mt.channel.prompt(ConsolePromptEvent(lastState.get))
+              case `attach` | "" => mt.channel.prompt(ConsolePromptEvent(lastState.get))
               case `Cancel` =>
                 Option(currentExecRef.get).foreach(cancel)
                 mt.channel.prompt(ConsolePromptEvent(lastState.get))