diff --git a/collects/lang/htdp-langs.ss b/collects/lang/htdp-langs.ss
index ec2ecc7054..822ce38e3f 100644
--- a/collects/lang/htdp-langs.ss
+++ b/collects/lang/htdp-langs.ss
@@ -1,11 +1,3 @@
-#|
-
-;; we don't use the built in debugging, use our own
-;; version here that has no bug icon and only
-;; annotates code that comes from editors.
-
-|#
-
 #lang scheme
 (require string-constants
            framework
@@ -39,7 +31,7 @@
            stepper/private/shared
            
            (only-in test-engine/scheme-gui make-formatter)
-           (only-in test-engine/scheme-tests scheme-test-data scheme-error-handler test-format test-execute)
+           (only-in test-engine/scheme-tests scheme-test-data error-handler test-format test-execute)
            (lib "test-engine/test-display.scm")
            )
   
@@ -176,7 +168,7 @@
                  (namespace-attach-module drs-namespace scheme-test-module-name)
                  (namespace-require scheme-test-module-name)
                  (scheme-test-data (list (drscheme:rep:current-rep) drs-eventspace test-display%))
-                 (scheme-error-handler teaching-languages-error-display-handler)
+                 (error-handler teaching-languages-error-display-handler)
                  (test-execute (get-preference 'tests:enable? (lambda () #t)))
                  (test-format (make-formatter (lambda (v o) (render-value/format v settings o 40))))
                  )))
diff --git a/collects/test-engine/scheme-tests.ss b/collects/test-engine/scheme-tests.ss
index 4de3915ba6..fa11b9233c 100644
--- a/collects/test-engine/scheme-tests.ss
+++ b/collects/test-engine/scheme-tests.ss
@@ -190,7 +190,8 @@
                (with-handlers ([exn? (lambda (e)
                                        #;((error-display-handler) (exn-message e) e)
                                        (list (make-unexpected-error src expect
-                                                                    (exn-message e) e) 'error e))])
+                                                                    (exn-message e) 
+                                                                    e) 'error (lambda () (test))))])
                  (let ([test-val (test)])
                    (cond [(check expect test-val range) (list #t test-val #f)]
                          [else 
@@ -290,7 +291,7 @@
 (define (insert-test test-info test) (send test-info add-test test))
 
 (define scheme-test-data (make-parameter (list #f #f #f)))
-(define scheme-error-handler (make-parameter (error-display-handler)))
+#;(define scheme-error-handler (make-parameter (error-display-handler)))
 
 (define scheme-test%
   (class* test-engine% ()
@@ -315,4 +316,4 @@
       (test)
       (inner (void) run-test test))))
 
-(provide scheme-test-data test-format test-execute test-silence scheme-error-handler)
+(provide scheme-test-data test-format test-execute test-silence error-handler)
diff --git a/collects/test-engine/test-display.scm b/collects/test-engine/test-display.scm
index b1f82ee58f..55cba9cb50 100644
--- a/collects/test-engine/test-display.scm
+++ b/collects/test-engine/test-display.scm
@@ -5,7 +5,8 @@
          mred
          framework
          string-constants
-         "test-info.scm")
+         "test-info.scm"
+         "test-engine.scm")
 
 (define test-display%
   (class* object% ()
@@ -112,10 +113,16 @@
     (define/public (display-check-failures checks editor test-info src-editor)
       (for ([failed-check (reverse checks)])
         (send editor insert "\t")
-        (make-link editor
-                   (failed-check-msg failed-check)
-                   (failed-check-src failed-check)
-                   src-editor)
+        (if (failed-check-exn? failed-check)
+            (make-error-link editor
+                             (failed-check-msg failed-check)
+                             (failed-check-exn? failed-check)
+                             (failed-check-src failed-check)
+                             src-editor)
+            (make-link editor
+                       (failed-check-msg failed-check)
+                       (failed-check-src failed-check)
+                       src-editor))
         (send editor insert "\n")))
 
     ;next-line: editor% -> void
@@ -144,7 +151,28 @@
                   start end #f)
             (send c set-delta-foreground "royalblue")
             (send text change-style c start end #f)))))
+    
+    ;; make-error-link: text% (listof (U string snip%)) exn src editor -> void
+    (define (make-error-link text msg exn dest src-editor)
+      (make-link text msg dest src-editor)
+      (let ((start (send text get-end-position)))
+        (send text insert "Trace error ")
+        (when (and src-editor current-rep)
+          (send text set-clickback
+                start (send text get-end-position)
+                (lambda (t s e) (parameterize ([error-display-handler (error-handler)])
+                                  (exn)))
+                #f #f)
+          (let ([end (send text get-end-position)]
+                [c (new style-delta%)])
+            (send text insert " ")
+            (send text change-style
+                  (make-object style-delta% 'change-underline #t)
+                  start end #f)
+            (send c set-delta-foreground "red")
+            (send text change-style c start end #f)))))
 
+    ;format-src: src -> string
     (define (format-src src)
       (let ([src-file car]
             [src-line cadr]
diff --git a/collects/test-engine/test-engine.scm b/collects/test-engine/test-engine.scm
index 6aeb8042f7..953a118b82 100644
--- a/collects/test-engine/test-engine.scm
+++ b/collects/test-engine/test-engine.scm
@@ -166,6 +166,7 @@
 
 (define test-format (make-parameter (lambda (v) (format "~a" v))))
 (define test-execute (make-parameter #t))
+(define error-handler (make-parameter (error-display-handler)))
 (define test-silence (make-parameter #f))
 
-(provide test-engine% test-display-textual% test-format test-execute test-silence)
+(provide test-engine% test-display-textual% test-format error-handler test-execute test-silence)
diff --git a/collects/test-engine/test-info.scm b/collects/test-engine/test-info.scm
index 1bf39865ae..b7db3e200a 100644
--- a/collects/test-engine/test-info.scm
+++ b/collects/test-engine/test-info.scm
@@ -5,7 +5,7 @@
 (provide (all-defined-out))
 
 ;; (make-failed-check src (listof (U string snip%)) (U #f exn))
-(define-struct failed-check (src msg exn))
+(define-struct failed-check (src msg exn?))
 
 (define test-info-base%
   (class* object% ()