The following code causes a segfault when run under Python3.4+ on OSX10.9.
# segfaulter.py
import asyncio
class A:
pass
class B:
def __init__(self, future):
self.future = future
def __del__(self):
self.a = None
@asyncio.coroutine
def do_work(future):
a = A()
b = B(asyncio.Future())
a.b = b
b.a = a
future.set_result(None)
future = asyncio.Future()
asyncio.Task(do_work(future))
loop = asyncio.get_event_loop()
loop.run_until_complete(future)
It does matter that the Future is passed to b's __init__ method.
It doesn't matter whether the Future has been resolved.
Attached is the problem report generated by OSX on the crash.