--- a/graal/com.oracle.truffle.sl/src/com/oracle/truffle/sl/builtins/SLStackTraceBuiltin.java	Tue May 26 16:46:25 2015 +0200
+++ b/graal/com.oracle.truffle.sl/src/com/oracle/truffle/sl/builtins/SLStackTraceBuiltin.java	Tue May 26 19:11:36 2015 +0200
@@ -52,20 +52,22 @@
         StringBuilder str = new StringBuilder();
 
         Truffle.getRuntime().iterateFrames(frameInstance -> {
-            dumpFrame(str, frameInstance.getCallTarget(), frameInstance.getFrame(FrameAccess.READ_ONLY, true));
+            CallTarget callTarget = frameInstance.getCallTarget();
+            Frame frame = frameInstance.getFrame(FrameAccess.READ_ONLY, true);
+            RootNode rn = ((RootCallTarget) callTarget).getRootNode();
+            if (rn.getClass().getName().contains("SLFunctionForeignAccess")) {
+                return 1;
+            }
+            if (str.length() > 0) {
+                str.append(System.getProperty("line.separator"));
+            }
+            str.append("Frame: ").append(rn.toString());
+            FrameDescriptor frameDescriptor = frame.getFrameDescriptor();
+            frameDescriptor.getSlots().stream().forEach((s) -> {
+                str.append(", ").append(s.getIdentifier()).append("=").append(frame.getValue(s));
+            });
             return null;
         });
         return str.toString();
     }
-
-    private static void dumpFrame(StringBuilder str, CallTarget callTarget, Frame frame) {
-        if (str.length() > 0) {
-            str.append(System.getProperty("line.separator"));
-        }
-        str.append("Frame: ").append(((RootCallTarget) callTarget).getRootNode().toString());
-        FrameDescriptor frameDescriptor = frame.getFrameDescriptor();
-        for (FrameSlot s : frameDescriptor.getSlots()) {
-            str.append(", ").append(s.getIdentifier()).append("=").append(frame.getValue(s));
-        }
-    }
 }