Some cleanup changes.

--
MOS_MIGRATED_REVID=87821306
diff --git a/src/main/java/com/google/devtools/build/lib/shell/Command.java b/src/main/java/com/google/devtools/build/lib/shell/Command.java
index 70c5f8a..364373d 100644
--- a/src/main/java/com/google/devtools/build/lib/shell/Command.java
+++ b/src/main/java/com/google/devtools/build/lib/shell/Command.java
@@ -876,7 +876,7 @@
       message.append(']');
     }
     message.append("; environment: ");
-    message.append(processBuilder.environment().toString());
+    message.append(processBuilder.environment());
     final File workingDirectory = processBuilder.directory();
     message.append("; working dir: ");
     message.append(workingDirectory == null ?