Watchdog blocks eventlet/Flask from running in debug mode.

[mortoray]

Simply having watchdog installed causes flask+eventlet to hang. I've filed this issue on eventlet, but I'm not sure where it belongs.
eventlet issue: eventlet/eventlet#634

There was previous issue here related to eventlet:
previous watchdog issue: #332

[merlinran]

To reproduce: eventlet/eventlet#634 (comment)

I encountered this because I installed pytest-watch in the Docker image, which depends on watchdog.

[BoboTiG]

I am far from efficient in that area. eventlet.monkey_patch(thread=False) fixes the issue :D

Now we need to find which part of the code is triggering the blocking.