diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 7e238772247..170ea3f8d16 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -25,6 +25,9 @@ Release 0.23.1 - Unreleased
    HADOOP-7787. Make source tarball use conventional name.
    (Bruno Mahé via tomwhite)
 
+   HADOOP-6614. RunJar should provide more diags when it can't create
+   a temp file. (Jonathan Hsieh via eli)
+
 Release 0.23.0 - 2011-11-01 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/RunJar.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/RunJar.java
index 46993e16aac..e6c6a14eeae 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/RunJar.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/RunJar.java
@@ -149,7 +149,17 @@ public class RunJar {
     File tmpDir = new File(new Configuration().get("hadoop.tmp.dir"));
     ensureDirectory(tmpDir);
 
-    final File workDir = File.createTempFile("hadoop-unjar", "", tmpDir);
+    File workDir;
+    try { 
+      workDir = File.createTempFile("hadoop-unjar", "", tmpDir);
+    } catch (IOException ioe) {
+      // if user has insufficient perms to write to tmpDir, default  
+      // "Permission denied" message doesn't specify a filename. 
+      System.err.println("Error creating temp dir in " + tmpDir + " due to " 
+          + ioe.getMessage());
+      System.exit(-1);
+    }
+
     if (!workDir.delete()) {
       System.err.println("Delete failed for " + workDir);
       System.exit(-1);