Can't display the stack details

[kanglue]

Traceback (most recent call last):
File "/home/jl/miniconda3/envs/vsumm/bin/pystack", line 10, in
sys.exit(main())
File "/home/jl/miniconda3/envs/vsumm/lib/python3.7/site-packages/click/core.py", line 700, in call
return self.main(*args, **kwargs)
File "/home/jl/miniconda3/envs/vsumm/lib/python3.7/site-packages/click/core.py", line 680, in main
rv = self.invoke(ctx)
File "/home/jl/miniconda3/envs/vsumm/lib/python3.7/site-packages/click/core.py", line 873, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/jl/miniconda3/envs/vsumm/lib/python3.7/site-packages/click/core.py", line 508, in invoke
return callback(*args, **kwargs)
File "/home/jl/miniconda3/envs/vsumm/lib/python3.7/site-packages/pystack.py", line 109, in main
return print_stack(pid, include_greenlet, debugger, verbose)
File "/home/jl/miniconda3/envs/vsumm/lib/python3.7/site-packages/pystack.py", line 89, in print_stack
sys.stdout.write(chunk)
TypeError: write() argument must be str, not bytes