working version 1

packages/system/virt/src/image_prep/mod.rs

@@ -204,7 +204,7 @@ if [ -z \"$NBD\" ]; then
   exit 1
 fi
 
-echo \"Selected NBD: $NBD\"
+echo \"Selected NBD: $NBD\" >&2
 
 # Settle and probe partitions
 udevadm settle >/dev/null 2>&1 || true
@@ -234,7 +234,7 @@ else
   exit 33
 fi
 
-echo \"ROOT_DEV=$ROOT_DEV BOOT_DEV=$BOOT_DEV\"
+echo \"ROOT_DEV=$ROOT_DEV BOOT_DEV=$BOOT_DEV\" >&2
 
 if [ ! -b \"$ROOT_DEV\" ]; then
   echo \"Root partition not found: $ROOT_DEV\" >&2
@@ -357,8 +357,10 @@ fi
 rm -f \"$RAW\"
 qemu-img convert -U -f qcow2 -O raw \"$WORK\" \"$RAW\"
 
-# Output result triple
-echo \"$RAW|$ROOT_UUID|$BOOT_UUID\"
+# Output result triple ONLY on stdout, then prevent any further trap output
+echo \"RESULT:$RAW|$ROOT_UUID|$BOOT_UUID\"
+trap - EXIT
+exit 0
 ",
                 src = shell_escape(&src),
                 vm_dir = shell_escape(&vm_dir),
@@ -374,8 +376,30 @@ echo \"$RAW|$ROOT_UUID|$BOOT_UUID\"
             );
 
             let res = run_script(&script)?;
-            let line = res.stdout.trim().lines().last().unwrap_or("").trim().to_string();
-            let parts: Vec<_> = line.split('|').map(|s| s.to_string()).collect();
+            // Prefer a RESULT:-prefixed line (robust against extra stdout noise)
+            let mut marker: Option<String> = None;
+            for l in res.stdout.lines().rev() {
+                let lt = l.trim();
+                if let Some(rest) = lt.strip_prefix("RESULT:") {
+                    marker = Some(rest.trim().to_string());
+                    break;
+                }
+            }
+            // Fallback: last line that looks like A|B|C
+            let line = if let Some(x) = marker {
+                x
+            } else {
+                let mut cand: Option<String> = None;
+                for l in res.stdout.lines().rev() {
+                    let lt = l.trim();
+                    if lt.split('|').count() == 3 {
+                        cand = Some(lt.to_string());
+                        break;
+                    }
+                }
+                cand.ok_or_else(|| fail("no RAW|ROOT_UUID|BOOT_UUID line found in script output"))?
+            };
+            let parts: Vec<_> = line.split('|').map(|s| s.trim().to_string()).collect();
             if parts.len() != 3 {
                 return Err(fail(&format!(
                     "unexpected output from image_prepare script, expected RAW|ROOT_UUID|BOOT_UUID, got: {}",