Hi!
I think I found some issue in the "print_stack()" function of asyncio.Task.
When I try to print the stack of some task, I only see the first few lines of the stack. 
Attached an example file, that contains a recursive function that after 10 calls prints the stack of the task. 
You can see that the stack that it prints only shows the first call of the recursive function, although you would expect to see it 10 times.

Tested on python3.7 and 3.8 on both MacOS and CentOS, the result is the same. 

Your help will be appreciated very much! :)