This should fix the len issue - though there may be better ways to fix

this.
This reverts commit d1e2d29211.

spiffworkflow-backend/src/spiffworkflow_backend/routes/process_instances_controller.py

@@ -125,6 +125,7 @@ def process_instance_run(
             raise e
         except Exception as e:
             ErrorHandlingService().handle_error(processor, e)
+            # fixme: this is going to point someone to the wrong task - it's misinformation for errors in sub-processes
             task = processor.bpmn_process_instance.last_task
             raise ApiError.from_task(
                 error_code="unknown_exception",

spiffworkflow-backend/src/spiffworkflow_backend/services/process_instance_processor.py

@@ -208,20 +208,21 @@ class NonTaskDataBasedScriptEngineEnvironment(BasePythonScriptEngineEnvironment)
         self.state.update(self.globals)
         self.state.update(external_methods or {})
         self.state.update(context)
-        exec(script, self.state)  # noqa
+        try:
+            exec(script, self.state)  # noqa
+        finally:
+            # since the task data is not directly mutated when the script executes, need to determine which keys
+            # have been deleted from the environment and remove them from task data if present.
+            context_keys_to_drop = context.keys() - self.state.keys()
 
-        # since the task data is not directly mutated when the script executes, need to determine which keys
-        # have been deleted from the environment and remove them from task data if present.
-        context_keys_to_drop = context.keys() - self.state.keys()
+            for key_to_drop in context_keys_to_drop:
+                context.pop(key_to_drop)
 
-        for key_to_drop in context_keys_to_drop:
-            context.pop(key_to_drop)
+            self.state = self._user_defined_state(external_methods)
 
-        self.state = self._user_defined_state(external_methods)
-
-        # the task data needs to be updated with the current state so data references can be resolved properly.
-        # the state will be removed later once the task is completed.
-        context.update(self.state)
+            # the task data needs to be updated with the current state so data references can be resolved properly.
+            # the state will be removed later once the task is completed.
+            context.update(self.state)
 
     def _user_defined_state(
         self, external_methods: Optional[Dict[str, Any]] = None

spiffworkflow-backend/src/spiffworkflow_backend/services/service_task_service.py

@@ -113,7 +113,7 @@ class ServiceTaskDelegate:
                 message = ServiceTaskDelegate.get_message_for_status(
                     proxied_response.status_code
                 )
-                error = f"Received an unexpected response from the service : {message}"
+                error = f"Received an unexpected response from service {name} : {message}"
                 if "error" in parsed_response:
                     error += parsed_response["error"]
                 if json_parse_error: