diff --git a/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/DiffUtil.java b/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/DiffUtil.java
new file mode 100644
index 00000000000..155311b0291
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/DiffUtil.java
@@ -0,0 +1,86 @@
+/*******************************************************************************
+ * Copyright (c) 2007 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * Intel Corporation - Initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.managedbuilder.testplugin;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.UnsupportedEncodingException;
+
+import org.eclipse.cdt.utils.spawner.ProcessFactory;
+
+public class DiffUtil {
+	private static final String DIFF_CMD = "diff -u";
+	private static DiffUtil fInstance;
+	
+	private DiffUtil(){
+		
+	}
+	
+	public static DiffUtil getInstance(){
+		if(fInstance == null)
+			fInstance = new DiffUtil();
+		return fInstance;
+	}
+	
+	private static String createCommand(String location1, String location2){
+		StringBuffer buf = new StringBuffer();
+		buf.append(DIFF_CMD).append(" ").append(location1).append(" ").append(location2);
+		return buf.toString(); 
+	}
+	
+	public String diff(String location1, String location2){
+		InputStream in = invokeDiff(location1, location2);
+		if(in == null)
+			return null;
+		
+		String charSet = null;
+		BufferedReader br;
+		if (null == charSet) { 
+			br = new BufferedReader(new InputStreamReader(in));
+		} else {
+			try {
+				br = new BufferedReader(new InputStreamReader(in, charSet));
+			} catch (UnsupportedEncodingException e) {
+				// TODO Auto-generated catch block
+				e.printStackTrace();
+				return null;
+			}
+		}
+		String line;
+		String prev_key = null; // previous key read and saved in envVars
+		String prev_value = null; // value of previous key
+		StringBuffer buf = new StringBuffer();
+		try {
+			while ((line = br.readLine()) != null) {
+				buf.append("\n");
+				buf.append(line);
+			}
+		} catch (IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return null;
+		}
+		return buf.toString();
+	}
+	
+	private InputStream invokeDiff(String location1, String location2){
+		try {
+			Process p = ProcessFactory.getFactory().exec(createCommand(location1, location2));
+			return p.getInputStream();
+		} catch (IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		return null;
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/ManagedBuildTestHelper.java b/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/ManagedBuildTestHelper.java
index 0395688e7f7..7333b9496aa 100644
--- a/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/ManagedBuildTestHelper.java
+++ b/build/org.eclipse.cdt.managedbuilder.core.tests/suite/org/eclipse/cdt/managedbuilder/testplugin/ManagedBuildTestHelper.java
@@ -391,7 +391,17 @@ public class ManagedBuildTestHelper {
 				buffer.append("but was:\n ");
 				buffer.append("\"").append(testBuffer).append("\"");
 				buffer.append("\n\n ");
-						
+				
+				buffer.append(">>>>>>>>>>>>>>>start diff: \n");
+				String location1 = getFileLocation(project, benchmarkFile);
+				String location2 = getFileLocation(project, testFile);
+				String diff = DiffUtil.getInstance().diff(location1, location2);
+				if(diff == null)
+					diff = "!diff failed!";
+				buffer.append(diff);
+				buffer.append("\n<<<<<<<<<<<end diff");
+				buffer.append("\n\n ");
+				
 				Assert.fail(buffer.toString());
 			} 
 		}
@@ -426,6 +436,9 @@ public class ManagedBuildTestHelper {
 		return true;
 	}
 
+	static public String getFileLocation(IProject project, IPath path){
+		return project.getLocation().append(path).toString();
+	}
 	static public StringBuffer readContentsStripLineEnds(IProject project, IPath path) {
 		StringBuffer buff = new StringBuffer();
 		IPath fullPath = project.getLocation().append(path);