RuntimeError: There is no current event loop in thread 'Thread-1'.

[luckydonald]

ERROR    teleflask.server.mixins._execute_command: 
         Failed calling command '/test' (<function test at 0x10f7836a8>):
         Traceback (most recent call last):
           File "/path/to/teleflask/teleflask/server/mixins.py", line 499, in _execute_command
             self.process_result(update, func(update, text))
           File "/path/to/teleflask/teleflask/server/base.py", line 526, in process_result
             from ..messages import Message
           File "/path/to/teleflask/teleflask/messages.py", line 230, in <module>
             class DocumentMessage(Message):
           File "/path/to/teleflask/teleflask/messages.py", line 315, in DocumentMessage
             def send(self, sender: PytgbotApiBot, receiver, reply_id)->PytgbotApiMessage:
           File "/path/to/teleflask/virtualenv3.6.venv/lib/python3.6/site-packages/backoff/_decorator.py", line 141, in decorate
             if asyncio.Task.current_task() is not None:
           File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/asyncio/events.py", line 671, in get_event_loop
             return get_event_loop_policy().get_event_loop()
           File "/usr/local/Cellar/python3/3.6.0/Frameworks/Python.framework/Versions/3.6/lib/python3.6/asyncio/events.py", line 583, in get_event_loop
             % threading.current_thread().name)
         RuntimeError: There is no current event loop in thread 'Thread-1'.

So what fails is:

asyncio.Task.current_task()

When calling teleflask/messages.py:315.
The actual fail in backoff is _decorator.py (function def decorate(target) after asyncio.iscoroutinefunction(target) was false.

For reference, this is luckydonald/teleflask@777953, running examples/example2.py. (Flask internal debug server)
Mac OS 10.9.5
Python 3.6.0 (via brew)

Python 3.6.0 (default, Jan  1 2017, 18:45:22) 
[GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.56)] on darwin

backoff: Maybe 1.4.0?

python -c 'from backoff import __version__ as v; print(v)'
importError: cannot import name '__version__'

[bgreen-litl]

@rutsky any thoughts on how to handle this?

I'm guessing there is an event loop in a background thread? The safety check we have here https://github.com/litl/backoff/blob/master/backoff/_decorator.py#L65 is what is blowing up.

[rutsky]

@bgreen-litl this is indeed bug in safety check. I haven't expected that missing global event loop will blow Task.current_task() in such way.
Take a look at #31 adding unit tests for that and fixing it.

[bgreen-litl]

@rutsky thank you! @luckydonald I will get a roll a 1.4.1 release with this fix. Thanks for the report.

[luckydonald]

👍 Awesome, thanks!
Btw, could you add a __version__ = "1.4.1" to the package root?

[bgreen-litl]

backoff==1.4.1 is released

@luckydonald I also exposed a __version__ attribute in the package root

[luckydonald]

Yeah! I'll try later today

[luckydonald]

Works. Fantastic.