From 8c004c1f36d3fa157733668d1fc5dbb5398c7a1b Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Tue, 14 Dec 2021 23:21:28 -0500
Subject: [PATCH] Add an explicit messaging error for reporting an illegal
 context transaction

---
 tractor/_portal.py | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tractor/_portal.py b/tractor/_portal.py
index 9b96bd20..1dc6ee46 100644
--- a/tractor/_portal.py
+++ b/tractor/_portal.py
@@ -27,6 +27,7 @@ from typing import (
 )
 from functools import partial
 from dataclasses import dataclass
+from pprint import pformat
 import warnings
 
 import trio
@@ -85,6 +86,9 @@ def _unwrap_msg(
         assert msg.get('cid'), "Received internal error at portal?"
         raise unpack_error(msg, channel)
 
+class MessagingError(Exception):
+    'Some kind of unexpected SC messaging dialog issue'
+
 
 class Portal:
     '''
@@ -408,8 +412,6 @@ class Portal:
             raise TypeError(
                 f'{func} must be an async generator function!')
 
-        __tracebackhide__ = True
-
         fn_mod_path, fn_name = func_deats(func)
 
         ctx = await self.actor.start_remote_task(
@@ -435,7 +437,10 @@ class Portal:
                 # raise kerr from unpack_error(msg, self.channel)
                 raise unpack_error(msg, self.channel) from None
             else:
-                raise
+                raise MessagingError(
+                    f'Context for {ctx.cid} was expecting a `started` message'
+                    f' but received a non-error msg:\n{pformat(msg)}'
+                )
 
         _err: Optional[BaseException] = None
         ctx._portal = self