From e04154b235501e7554d9c11acb01ce2f4f2834bf Mon Sep 17 00:00:00 2001
From: Mikhail Klementev <blame@dumpstack.io>
Date: Wed, 26 Apr 2023 14:35:20 +0000
Subject: [PATCH] Fix stderr log

---
 qemu/qemu-kernel.go | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/qemu/qemu-kernel.go b/qemu/qemu-kernel.go
index 73a67b7..6d900c4 100644
--- a/qemu/qemu-kernel.go
+++ b/qemu/qemu-kernel.go
@@ -378,7 +378,11 @@ func (q System) Command(user, cmd string) (output string, err error) {
 	if err != nil {
 		return
 	}
-	session.Stderr = session.Stdout
+
+	stderr, err := session.StderrPipe()
+	if err != nil {
+		return
+	}
 
 	err = session.Start(cmd)
 	if err != nil {
@@ -395,6 +399,17 @@ func (q System) Command(user, cmd string) (output string, err error) {
 		output = strings.TrimSuffix(output, "\n")
 	}()
 
+	go func() {
+		scanner := bufio.NewScanner(stderr)
+		for scanner.Scan() {
+			m := scanner.Text()
+			output += m + "\n"
+			// Note: it prints stderr as stdout
+			flog.Trace().Str("stdout", m).Msg("")
+		}
+		output = strings.TrimSuffix(output, "\n")
+	}()
+
 	err = session.Wait()
 	return
 }