bpo-32047: -X dev enables asyncio debug mode (#4418)

The new -X dev command line option now also enables asyncio debug
mode.

1 files changed, 19 insertions, 11 deletions

diff --git a/Lib/asyncio/coroutines.py b/Lib/asyncio/coroutines.py
index 520a309..a87c9f9 100644
--- a/Lib/asyncio/coroutines.py
+++ b/Lib/asyncio/coroutines.py
@@ -19,17 +19,25 @@ from .log import logger
 # Opcode of "yield from" instruction
 _YIELD_FROM = opcode.opmap['YIELD_FROM']
 
-# If you set _DEBUG to true, @coroutine will wrap the resulting
-# generator objects in a CoroWrapper instance (defined below).  That
-# instance will log a message when the generator is never iterated
-# over, which may happen when you forget to use "yield from" with a
-# coroutine call.  Note that the value of the _DEBUG flag is taken
-# when the decorator is used, so to be of any use it must be set
-# before you define your coroutines.  A downside of using this feature
-# is that tracebacks show entries for the CoroWrapper.__next__ method
-# when _DEBUG is true.
-_DEBUG = (not sys.flags.ignore_environment and
-          bool(os.environ.get('PYTHONASYNCIODEBUG')))
+
+def _is_debug_mode():
+    # If you set _DEBUG to true, @coroutine will wrap the resulting
+    # generator objects in a CoroWrapper instance (defined below).  That
+    # instance will log a message when the generator is never iterated
+    # over, which may happen when you forget to use "yield from" with a
+    # coroutine call.  Note that the value of the _DEBUG flag is taken
+    # when the decorator is used, so to be of any use it must be set
+    # before you define your coroutines.  A downside of using this feature
+    # is that tracebacks show entries for the CoroWrapper.__next__ method
+    # when _DEBUG is true.
+    debug = (not sys.flags.ignore_environment and
+             bool(os.environ.get('PYTHONASYNCIODEBUG')))
+    if hasattr(sys, '_xoptions') and 'dev' in sys._xoptions:
+        debug = True
+    return debug
+
+
+_DEBUG = _is_debug_mode()
 
 
 try: