--- maven2-plugins/maven-assembly-plugin/src/main/java/org/apache/maven/plugin/assembly/format/FileFormatter.java.sav	2010-11-28 16:15:25.000000000 +0100
+++ maven2-plugins/maven-assembly-plugin/src/main/java/org/apache/maven/plugin/assembly/format/FileFormatter.java	2010-11-28 16:17:43.000000000 +0100
@@ -163,8 +163,12 @@
         interpolator.addValueSource( new MapBasedValueSource( filterProperties ) );
         interpolator.addValueSource( new ObjectBasedValueSource( configSource.getProject() ) );
 
-        contents = interpolator.interpolate( contents, "project" );
-
+        try {
+            contents = interpolator.interpolate( contents, "project" );
+        } catch(Exception e) {
+            throw new AssemblyFormattingException( "cannot interpolate contents: " + e.getMessage(), e );
+        }
+ 
         return contents;
     }