Failing test: an exception in a stop script messes up cleanup

syndicate/syntax.rkt

@@ -612,6 +612,32 @@
           )
 
         (lambda ()
+          ;; Goal: no matter the circumstances (e.g. exception in a
+          ;; stop script), we will never retract an assertion more or
+          ;; fewer than the correct number of times.
+
+          ;; Test cleanup after exception in stop script
+          ;;
+          ;; Correct output:
+          ;;
+          ;; inner gone
+          ;; outer gone
+          ;; middle gone
+          ;;
+          ;; (or some permutation of these) plus an exception report for the division by zero.
+
+          (assertion-struct layer (name))
+
+          (spawn (define root-facet (current-facet))
+                 (assert (layer 'outer))
+                 (on-start (react (assert (layer 'middle))
+                                  (on-start (flush!) (flush!) (stop-facet root-facet))
+                                  (on-stop (/ 1 0))
+                                  (on-start (react (assert (layer 'inner)))))))
+
+          (spawn (on (retracted (layer $x)) (printf "~a gone\n" x))))
+
+        #;(lambda ()
           (spawn #:name 'factory-1
                  (on (asserted (list 'X 1))
                      (spawn #:name 'service-1