1 files changed, 2 insertions, 1 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/vfs/Path.java b/src/main/java/com/google/devtools/build/lib/vfs/Path.java
index b41589caae..a1436b5178 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/Path.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/Path.java
@@ -216,7 +216,8 @@ public class Path implements Comparable<Path>, Serializable {
   }
 
   private void writeObject(ObjectOutputStream out) throws IOException {
-    Preconditions.checkState(fileSystem == fileSystemForSerialization, fileSystem);
+    Preconditions.checkState(
+        fileSystem == fileSystemForSerialization, "%s %s", fileSystem, fileSystemForSerialization);
     out.writeUTF(getPathString());
   }