--- /mnt/storage/scratch/rocko-r82-out/mutants-base/orig	2026-10-11 20:30:15.852477467 -0500
+++ scripts/mosaic-task.mjs	2026-10-11 20:30:19.921452775 -0500
@@ -480,7 +480,7 @@
       if (typeof result.status === "string") status = result.status;
       if (typeof result.taskId === "string") taskId = result.taskId;
       if (typeof result.workspace === "string") workspace = result.workspace;
-      if (typeof result.session === "string") session = result.session;
+      session = result.session ?? "-";
     }
     process.stdout.write(`${runId}  ${status.padEnd(9)}  task=${taskId.padEnd(18)} ws=${workspace.padEnd(10)} session=${session}\n`);
   }