diff --git a/core/actor.lisp b/core/actor.lisp
index 6ce553a..1bc58bb 100644
--- a/core/actor.lisp
+++ b/core/actor.lisp
@@ -61,9 +61,9 @@
   (let ((*self* tsk))
     (handler-case (funcall bhv msg)
       (error (err) 
-             ;(util:lg :error "behavior" msg err)
-             (invoke-debugger err))
-      )))
+             (invoke-debugger err)
+             (util:lg :error "behavior" msg err)
+             ))))
 
 ;;;; the core (classical, i.e. Hewitt) actor API
 
diff --git a/test/etc/config-csys.lisp b/test/etc/config-csys.lisp
index 429520f..db0b307 100644
--- a/test/etc/config-csys.lisp
+++ b/test/etc/config-csys.lisp
@@ -4,7 +4,10 @@
 
 (config:root)
 
-(config:add-action '(:csys :sensor :log) (csys:neuron #'csys:logger :testing))
+(config:add-action '(:csys :sensor :log) 
+                   (csys:neuron #'csys:logger :testing
+                                (list (csys:synapse *probe*))
+                                ))
 
 (config:add :logger  :class 'logging:config
             :loglevel (config:from-env :loglevel :info)
diff --git a/test/test-csys.lisp b/test/test-csys.lisp
index 4869855..5cd2da3 100644
--- a/test/test-csys.lisp
+++ b/test/test-csys.lisp
@@ -18,24 +18,39 @@
 
 (in-package :scopes/test-csys)
 
+;;;; testing environment
+
+(defclass test-env (csys:environment)
+  ((test-suite :reader test-suite :initarg :test-suite)))
+
+(defun probe (msg state syns env)
+  (let ((t:*test-suite* (test-suite env)))
+    (== (shape:data msg) (pop state))
+    (actor:become (csys:neuron #'probe state syns env))))
+
+(defvar *probe* nil)
+
 ;;;; test runner
 
 (defun run ()
   (async:init)
   (let* ((t:*test-suite* (make-instance 't:test-suite :name "csys"))
-         (csys:*sensors* (make-hash-table :test #'equal)))
+         (csys:*sensors* (make-hash-table :test #'equal))
+         (csys:*environment* (make-instance 'test-env :test-suite t:*test-suite*))
+         (*probe* (actor:create 
+                    (csys:neuron #'probe '(1 3 4 5) nil csys:*environment*))))
     (load (t:test-path "config-csys" "etc"))
+    (core:setup-services)
     (unwind-protect
       (progn
-        (test-nodispatch))
+        (test-basic))
+      (sleep 0.1)
       (async:finish)
       (t:show-result))))
 
-(deftest test-nodispatch ()
-  (core:setup-services)
+(deftest test-basic ()
   (csys:send-message '(:csys :add :log :s1) 1)
   (csys:send-message '(:csys :add :log :s1) 3)
   (csys:send-message '(:csys :sub :log :s2) 4)
   (csys:send-message '(:csys :add :log :s2) 5)
-  (sleep 0.1)
 )