asyncio, Tulip issue #136: Add get/set_debug() methods to BaseEventLoopTests.
Add also a PYTHONASYNCIODEBUG environment variable to debug coroutines since
Python startup, to be able to debug coroutines defined directly in the asyncio
module.
diff --git a/Doc/library/asyncio-dev.rst b/Doc/library/asyncio-dev.rst
index 90bae84..c5f0d1a 100644
--- a/Doc/library/asyncio-dev.rst
+++ b/Doc/library/asyncio-dev.rst
@@ -1,5 +1,7 @@
.. currentmodule:: asyncio
+.. _asyncio-dev:
+
Develop with asyncio
====================
@@ -81,10 +83,10 @@
When a coroutine function is called but not passed to :func:`async` or to the
:class:`Task` constructor, it is not scheduled and it is probably a bug.
-To detect such bug, set :data:`asyncio.tasks._DEBUG` to ``True``. When the
-coroutine object is destroyed by the garbage collector, a log will be emitted
-with the traceback where the coroutine function was called. See the
-:ref:`asyncio logger <asyncio-logger>`.
+To detect such bug, set the environment variable :envvar:`PYTHONASYNCIODEBUG`
+to ``1``. When the coroutine object is destroyed by the garbage collector, a
+log will be emitted with the traceback where the coroutine function was called.
+See the :ref:`asyncio logger <asyncio-logger>`.
The debug flag changes the behaviour of the :func:`coroutine` decorator. The
debug flag value is only used when then coroutine function is defined, not when