From 05cd00e13544f4c6d2be50777bfdccdbf7762186 Mon Sep 17 00:00:00 2001
From: BitToby <218712309+bittoby@users.noreply.github.com>
Date: Mon, 13 Apr 2026 00:24:30 +0200
Subject: [PATCH] [2.x] fix: stack traces suppressed in thin client batch mode
 (#9058)

In sbt 2.x, running batch commands through the thin client (sbtn) suppresses stack traces for all tasks because the server's shell command unconditionally sets state.interactive = true. This causes LogManager.defaultTraceLevel to return -1 (suppressed) even when the client explicitly signals non-interactive (batch) mode via Attach(interactive=false).

This fixes the shell command to check the originating NetworkChannel's interactive flag before setting state.interactive, so thin client batch commands correctly get Int.MaxValue trace level and display full stack traces.
---
 main/src/main/scala/sbt/Main.scala                    | 10 +++++++++-
 .../sbt-test/actions/streams-trace-level/build.sbt    | 11 +++++++++++
 sbt-app/src/sbt-test/actions/streams-trace-level/test |  2 ++
 3 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 sbt-app/src/sbt-test/actions/streams-trace-level/build.sbt
 create mode 100644 sbt-app/src/sbt-test/actions/streams-trace-level/test

diff --git a/main/src/main/scala/sbt/Main.scala b/main/src/main/scala/sbt/Main.scala
index f7bbb12b9..37fe90b49 100644
--- a/main/src/main/scala/sbt/Main.scala
+++ b/main/src/main/scala/sbt/Main.scala
@@ -1144,12 +1144,20 @@ object BuiltinCommands {
         .getOpt(Keys.minForcegcInterval)
         .getOrElse(GCUtil.defaultMinForcegcInterval)
       val exec: Exec = getExec(s1, minGCInterval)
+      val isInteractive = exec.source match {
+        case Some(src) if src.channelName.startsWith("network") =>
+          exchange.channelForName(src.channelName) match {
+            case Some(nc: NetworkChannel) => nc.isInteractive
+            case _                        => true
+          }
+        case _ => true
+      }
       val newState = s1
         .copy(
           onFailure = Some(Exec(Shell, None)),
           remainingCommands = exec +: Exec(Shell, None) +: s1.remainingCommands
         )
-        .setInteractive(true)
+        .setInteractive(isInteractive)
       val res =
         if (exec.commandLine.trim.isEmpty) newState
         else newState.clearGlobalLog
diff --git a/sbt-app/src/sbt-test/actions/streams-trace-level/build.sbt b/sbt-app/src/sbt-test/actions/streams-trace-level/build.sbt
new file mode 100644
index 000000000..e2b32014e
--- /dev/null
+++ b/sbt-app/src/sbt-test/actions/streams-trace-level/build.sbt
@@ -0,0 +1,11 @@
+lazy val helloWithoutStreams = taskKey[Unit]("")
+lazy val helloWithStreams = taskKey[Unit]("")
+
+helloWithoutStreams := {
+  throw new RuntimeException("boom without streams!")
+}
+
+helloWithStreams := {
+  val log = streams.value.log
+  throw new RuntimeException("boom with streams!")
+}
diff --git a/sbt-app/src/sbt-test/actions/streams-trace-level/test b/sbt-app/src/sbt-test/actions/streams-trace-level/test
new file mode 100644
index 000000000..92bc6373f
--- /dev/null
+++ b/sbt-app/src/sbt-test/actions/streams-trace-level/test
@@ -0,0 +1,2 @@
+-> helloWithoutStreams
+-> helloWithStreams