1 files changed, 6 insertions, 1 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/util/OS.java b/src/main/java/com/google/devtools/build/lib/util/OS.java
index 04e437b8f2..97e6c3a13a 100644
--- a/src/main/java/com/google/devtools/build/lib/util/OS.java
+++ b/src/main/java/com/google/devtools/build/lib/util/OS.java
@@ -20,7 +20,7 @@ public enum OS {
   DARWIN("osx", "Mac OS X"),
   LINUX("linux", "Linux"),
   WINDOWS("windows", "Windows"),
-  UNKNOWN("", "");
+  UNKNOWN("unknown", "");
 
   private final String canonicalName;
   private final String detectionName;
@@ -41,6 +41,11 @@ public enum OS {
     return canonicalName;
   }
 
+  @Override
+  public String toString() {
+    return getCanonicalName();
+  }
+
   // We inject a the OS name through blaze.os, so we can have
   // some coverage for Windows specific code on Linux.
   private static OS determineCurrentOs() {